diff --git a/.gitignore b/.gitignore
index 2d10cf601..2a5b30f19 100644
--- a/.gitignore
+++ b/.gitignore
@@ -24,3 +24,5 @@ build/daemon.zip
 .vimrc
 
 package-lock.json
+
+.DS_Store
diff --git a/CHANGELOG.md b/CHANGELOG.md
index cae3c17e6..1273376a1 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -21,6 +21,7 @@ Web UI version numbers should always match the corresponding version of LBRY App
   * Fixed scriolling restore/reset/set (#729)
   * Fixed sorting by title for published files (#614)
   * App now uses the new balance_delta field in the txn list.
+  * Abandoning from the claim page now works.
   *
 
 ### Deprecated
diff --git a/src/renderer/.flowconfig b/src/renderer/.flowconfig
new file mode 100644
index 000000000..18e154135
--- /dev/null
+++ b/src/renderer/.flowconfig
@@ -0,0 +1,17 @@
+[ignore]
+.*/node_modules/**
+
+[include]
+
+[libs]
+flow-typed
+
+[lints]
+
+[options]
+suppress_comment=\\(.\\|\n\\)*\\$FlowFixMe
+suppress_comment=\\(.\\|\n\\)*\\$FlowIssue
+module.name_mapper='^constants\(.*\)$' -> '<PROJECT_ROOT>/js/constants\1'
+module.name_mapper='^redux\(.*\)$' -> '<PROJECT_ROOT>/js/redux\1'
+
+[strict]
diff --git a/src/renderer/component/common.js b/src/renderer/component/common.js
index 010bd8f31..c5352637b 100644
--- a/src/renderer/component/common.js
+++ b/src/renderer/component/common.js
@@ -1,13 +1,14 @@
 import React from "react";
+import PropTypes from "prop-types";
 import { formatCredits, formatFullPrice } from "util/formatCredits";
 import lbry from "../lbry.js";
 
 //component/icon.js
 export class Icon extends React.PureComponent {
   static propTypes = {
-    icon: React.PropTypes.string.isRequired,
-    className: React.PropTypes.string,
-    fixed: React.PropTypes.bool,
+    icon: PropTypes.string.isRequired,
+    className: PropTypes.string,
+    fixed: PropTypes.bool,
   };
 
   render() {
@@ -24,7 +25,7 @@ export class Icon extends React.PureComponent {
 
 export class TruncatedText extends React.PureComponent {
   static propTypes = {
-    lines: React.PropTypes.number,
+    lines: PropTypes.number,
   };
 
   static defaultProps = {
@@ -45,7 +46,7 @@ export class TruncatedText extends React.PureComponent {
 
 export class BusyMessage extends React.PureComponent {
   static propTypes = {
-    message: React.PropTypes.string,
+    message: PropTypes.string,
   };
 
   render() {
@@ -65,14 +66,14 @@ export class CurrencySymbol extends React.PureComponent {
 
 export class CreditAmount extends React.PureComponent {
   static propTypes = {
-    amount: React.PropTypes.number.isRequired,
-    precision: React.PropTypes.number,
-    isEstimate: React.PropTypes.bool,
-    label: React.PropTypes.bool,
-    showFree: React.PropTypes.bool,
-    showFullPrice: React.PropTypes.bool,
-    showPlus: React.PropTypes.bool,
-    look: React.PropTypes.oneOf(["indicator", "plain", "fee"]),
+    amount: PropTypes.number.isRequired,
+    precision: PropTypes.number,
+    isEstimate: PropTypes.bool,
+    label: PropTypes.bool,
+    showFree: PropTypes.bool,
+    showFullPrice: PropTypes.bool,
+    showPlus: PropTypes.bool,
+    look: PropTypes.oneOf(["indicator", "plain", "fee"]),
   };
 
   static defaultProps = {
@@ -142,7 +143,7 @@ let addressStyle = {
 };
 export class Address extends React.PureComponent {
   static propTypes = {
-    address: React.PropTypes.string,
+    address: PropTypes.string,
   };
 
   constructor(props) {
@@ -174,7 +175,7 @@ export class Address extends React.PureComponent {
 
 export class Thumbnail extends React.PureComponent {
   static propTypes = {
-    src: React.PropTypes.string,
+    src: PropTypes.string,
   };
 
   handleError() {
diff --git a/src/renderer/component/file-selector.js b/src/renderer/component/file-selector.js
index 2c3189c2f..adc481782 100644
--- a/src/renderer/component/file-selector.js
+++ b/src/renderer/component/file-selector.js
@@ -1,11 +1,12 @@
 import React from "react";
+import PropTypes from "prop-types";
 
 const { remote } = require("electron");
 class FileSelector extends React.PureComponent {
   static propTypes = {
-    type: React.PropTypes.oneOf(["file", "directory"]),
-    initPath: React.PropTypes.string,
-    onFileChosen: React.PropTypes.func,
+    type: PropTypes.oneOf(["file", "directory"]),
+    initPath: PropTypes.string,
+    onFileChosen: PropTypes.func,
   };
 
   static defaultProps = {
diff --git a/src/renderer/component/form.js b/src/renderer/component/form.js
index 03bf1185e..820ae251c 100644
--- a/src/renderer/component/form.js
+++ b/src/renderer/component/form.js
@@ -1,4 +1,5 @@
 import React from "react";
+import PropTypes from "prop-types";
 import FormField from "component/formField";
 import { Icon } from "component/common.js";
 
@@ -12,7 +13,7 @@ export function formFieldId() {
 
 export class Form extends React.PureComponent {
   static propTypes = {
-    onSubmit: React.PropTypes.func.isRequired,
+    onSubmit: PropTypes.func.isRequired,
   };
 
   constructor(props) {
@@ -35,15 +36,9 @@ export class Form extends React.PureComponent {
 
 export class FormRow extends React.PureComponent {
   static propTypes = {
-    label: React.PropTypes.oneOfType([
-      React.PropTypes.string,
-      React.PropTypes.element,
-    ]),
-    errorMessage: React.PropTypes.oneOfType([
-      React.PropTypes.string,
-      React.PropTypes.object,
-    ]),
-    // helper: React.PropTypes.html,
+    label: PropTypes.oneOfType([PropTypes.string, PropTypes.element]),
+    errorMessage: PropTypes.oneOfType([PropTypes.string, PropTypes.object]),
+    // helper: PropTypes.html,
   };
 
   static defaultProps = {
diff --git a/src/renderer/component/formField/view.jsx b/src/renderer/component/formField/view.jsx
index e93559eb0..bb8cc5024 100644
--- a/src/renderer/component/formField/view.jsx
+++ b/src/renderer/component/formField/view.jsx
@@ -1,4 +1,5 @@
 import React from "react";
+import PropTypes from "prop-types";
 import FileSelector from "component/file-selector.js";
 import SimpleMDE from "react-simplemde-editor";
 import { formFieldNestedLabelTypes, formFieldId } from "../form";
@@ -8,14 +9,14 @@ const formFieldFileSelectorTypes = ["file", "directory"];
 
 class FormField extends React.PureComponent {
   static propTypes = {
-    type: React.PropTypes.string.isRequired,
-    prefix: React.PropTypes.string,
-    postfix: React.PropTypes.string,
-    hasError: React.PropTypes.bool,
-    trim: React.PropTypes.bool,
-    regexp: React.PropTypes.oneOfType([
-      React.PropTypes.instanceOf(RegExp),
-      React.PropTypes.string,
+    type: PropTypes.string.isRequired,
+    prefix: PropTypes.string,
+    postfix: PropTypes.string,
+    hasError: PropTypes.bool,
+    trim: PropTypes.bool,
+    regexp: PropTypes.oneOfType([
+      PropTypes.instanceOf(RegExp),
+      PropTypes.string,
     ]),
   };
 
diff --git a/src/renderer/component/icon/view.jsx b/src/renderer/component/icon/view.jsx
index 5c23af877..ff772c467 100644
--- a/src/renderer/component/icon/view.jsx
+++ b/src/renderer/component/icon/view.jsx
@@ -1,10 +1,11 @@
 import React from "react";
+import PropTypes from "prop-types";
 import * as icons from "constants/icons";
 
 export default class Icon extends React.PureComponent {
   static propTypes = {
-    icon: React.PropTypes.string.isRequired,
-    fixed: React.PropTypes.bool,
+    icon: PropTypes.string.isRequired,
+    fixed: PropTypes.bool,
   };
 
   static defaultProps = {
diff --git a/src/renderer/component/load_screen.js b/src/renderer/component/load_screen.js
index 8304b2a5f..788e42cf1 100644
--- a/src/renderer/component/load_screen.js
+++ b/src/renderer/component/load_screen.js
@@ -1,13 +1,14 @@
 import React from "react";
+import PropTypes from "prop-types";
 import lbry from "../lbry.js";
 import { BusyMessage, Icon } from "./common.js";
 import Link from "component/link";
 
 class LoadScreen extends React.PureComponent {
   static propTypes = {
-    message: React.PropTypes.string.isRequired,
-    details: React.PropTypes.string,
-    isWarning: React.PropTypes.bool,
+    message: PropTypes.string.isRequired,
+    details: PropTypes.string,
+    isWarning: PropTypes.bool,
   };
 
   constructor(props) {
diff --git a/src/renderer/component/menu.js b/src/renderer/component/menu.js
index 6010c0b8f..d1b533077 100644
--- a/src/renderer/component/menu.js
+++ b/src/renderer/component/menu.js
@@ -1,13 +1,14 @@
 import React from "react";
+import PropTypes from "prop-types";
 import { Icon } from "./common.js";
 import Link from "component/link";
 
 export class DropDownMenuItem extends React.PureComponent {
   static propTypes = {
-    href: React.PropTypes.string,
-    label: React.PropTypes.string,
-    icon: React.PropTypes.string,
-    onClick: React.PropTypes.func,
+    href: PropTypes.string,
+    label: PropTypes.string,
+    icon: PropTypes.string,
+    onClick: PropTypes.func,
   };
 
   static defaultProps = {
diff --git a/src/renderer/component/publishForm/index.js b/src/renderer/component/publishForm/index.js
index a55cf9187..df41581d9 100644
--- a/src/renderer/component/publishForm/index.js
+++ b/src/renderer/component/publishForm/index.js
@@ -1,5 +1,10 @@
 import React from "react";
 import { connect } from "react-redux";
 import PublishForm from "./view";
+import { selectBalance } from "redux/selectors/wallet";
 
-export default connect(null, null)(PublishForm);
+const select = state => ({
+  balance: selectBalance(state),
+});
+
+export default connect(select, null)(PublishForm);
diff --git a/src/renderer/component/publishForm/internal/channelSection.jsx b/src/renderer/component/publishForm/internal/channelSection.jsx
index 203e90e74..49c560f65 100644
--- a/src/renderer/component/publishForm/internal/channelSection.jsx
+++ b/src/renderer/component/publishForm/internal/channelSection.jsx
@@ -48,11 +48,22 @@ class ChannelSection extends React.PureComponent {
 
   handleNewChannelBidChange(event) {
     this.setState({
-      newChannelBid: event.target.value,
+      newChannelBid: parseFloat(event.target.value),
     });
   }
 
   handleCreateChannelClick(event) {
+    const { balance } = this.props;
+    const { newChannelBid } = this.state;
+
+    if (newChannelBid > balance) {
+      this.refs.newChannelName.showError(
+        __("Unable to create channel due to insufficient funds.")
+      );
+
+      return;
+    }
+
     this.setState({
       creatingChannel: true,
     });
diff --git a/src/renderer/component/publishForm/view.jsx b/src/renderer/component/publishForm/view.jsx
index 75ac22d2b..deb16e248 100644
--- a/src/renderer/component/publishForm/view.jsx
+++ b/src/renderer/component/publishForm/view.jsx
@@ -61,6 +61,15 @@ class PublishForm extends React.PureComponent {
   }
 
   handleSubmit() {
+    const { balance } = this.props;
+    const { bid } = this.state;
+
+    if (bid > balance) {
+      this.handlePublishError({ message: "insufficient funds" });
+
+      return;
+    }
+
     this.setState({
       submitting: true,
     });
diff --git a/src/renderer/component/splash/view.jsx b/src/renderer/component/splash/view.jsx
index 6d4ed62a4..eabe723c5 100644
--- a/src/renderer/component/splash/view.jsx
+++ b/src/renderer/component/splash/view.jsx
@@ -1,4 +1,5 @@
 import React from "react";
+import PropTypes from "prop-types";
 import lbry from "lbry.js";
 import LoadScreen from "../load_screen.js";
 import ModalIncompatibleDaemon from "modal/modalIncompatibleDaemon";
@@ -8,8 +9,8 @@ import * as modals from "constants/modal_types";
 
 export class SplashScreen extends React.PureComponent {
   static propTypes = {
-    message: React.PropTypes.string,
-    onLoadDone: React.PropTypes.func,
+    message: PropTypes.string,
+    onLoadDone: PropTypes.func,
   };
 
   constructor(props) {
diff --git a/src/renderer/component/tooltip.js b/src/renderer/component/tooltip.js
index 7f694c7dc..6f1437405 100644
--- a/src/renderer/component/tooltip.js
+++ b/src/renderer/component/tooltip.js
@@ -1,9 +1,10 @@
 import React from "react";
+import PropTypes from "prop-types";
 
 export class ToolTip extends React.PureComponent {
   static propTypes = {
-    body: React.PropTypes.string.isRequired,
-    label: React.PropTypes.string.isRequired,
+    body: PropTypes.string.isRequired,
+    label: PropTypes.string.isRequired,
   };
 
   constructor(props) {
diff --git a/src/renderer/component/truncatedMarkdown/view.jsx b/src/renderer/component/truncatedMarkdown/view.jsx
index 9146855f1..ba060016b 100644
--- a/src/renderer/component/truncatedMarkdown/view.jsx
+++ b/src/renderer/component/truncatedMarkdown/view.jsx
@@ -1,10 +1,11 @@
 import React from "react";
+import PropTypes from "prop-types";
 import ReactMarkdown from "react-markdown";
 import ReactDOMServer from "react-dom/server";
 
 class TruncatedMarkdown extends React.PureComponent {
   static propTypes = {
-    lines: React.PropTypes.number,
+    lines: PropTypes.number,
   };
 
   static defaultProps = {
diff --git a/src/renderer/component/wunderbar/view.jsx b/src/renderer/component/wunderbar/view.jsx
index 04ba1a030..b23dc2218 100644
--- a/src/renderer/component/wunderbar/view.jsx
+++ b/src/renderer/component/wunderbar/view.jsx
@@ -1,4 +1,5 @@
 import React from "react";
+import PropTypes from "prop-types";
 import lbryuri from "lbryuri.js";
 import { Icon } from "component/common.js";
 import { parseQueryParams } from "util/query_params";
@@ -7,8 +8,8 @@ class WunderBar extends React.PureComponent {
   static TYPING_TIMEOUT = 800;
 
   static propTypes = {
-    onSearch: React.PropTypes.func.isRequired,
-    onSubmit: React.PropTypes.func.isRequired,
+    onSearch: PropTypes.func.isRequired,
+    onSubmit: PropTypes.func.isRequired,
   };
 
   constructor(props) {
diff --git a/src/renderer/flow-typed/electron.js b/src/renderer/flow-typed/electron.js
new file mode 100644
index 000000000..4c575c618
--- /dev/null
+++ b/src/renderer/flow-typed/electron.js
@@ -0,0 +1,3 @@
+declare module 'electron' {
+  declare module.exports: any;
+}
diff --git a/src/renderer/flowtype-plugin.js b/src/renderer/flowtype-plugin.js
new file mode 100644
index 000000000..8a33c707f
--- /dev/null
+++ b/src/renderer/flowtype-plugin.js
@@ -0,0 +1,116 @@
+var spawnSync = require('child_process').spawnSync;
+var flow = require('flow-bin');
+var merge = require('lodash.merge');
+
+var store = {
+  error: null,
+  flowOptions: [
+    'status',
+    '--color=always',
+  ],
+  options: {
+    warn: false,
+
+    formatter: function (errorCode, errorDetails) {
+      return 'Flow: ' + errorCode + '\n\n' + errorDetails;
+    },
+  },
+};
+
+
+function flowErrorCode(status) {
+  var error;
+  switch (status) {
+    /*
+    case 0:
+      error = null;
+      break;
+    */
+    case 1:
+      error = 'Server Initializing';
+      break;
+    case 2:
+      error = 'Type Error';
+      break;
+    case 3:
+      error = 'Out of Time';
+      break;
+    case 4:
+      error = 'Kill Error';
+      break;
+    case 6:
+      error = 'No Server Running';
+      break;
+    case 7:
+      error = 'Out of Retries';
+      break;
+    case 8:
+      error = 'Invalid Flowconfig';
+      break;
+    case 9:
+      error = 'Build Id Mismatch';
+      break;
+    case 10:
+      error = 'Input Error';
+      break;
+    case 11:
+      error = 'Lock Stolen';
+      break;
+    case 12:
+      error = 'Could Not Find Flowconfig';
+      break;
+    case 13:
+      error = 'Server Out of Date';
+      break;
+    case 14:
+      error = 'Server Client Directory Mismatch';
+      break;
+    case 15:
+      error = 'Out of Shared Memory';
+      break;
+  }
+
+  return error;
+}
+
+
+function checkFlowStatus(compiler, next) {
+  var res = spawnSync(flow, store.flowOptions);
+  var status = res.status;
+
+  if (status !== 0) {
+    var errorCode = flowErrorCode(status);
+    var errorDetails = res.stdout.toString() + res.stderr.toString();
+
+    store.error = new Error(store.options.formatter(errorCode, errorDetails));
+  }
+
+  next();
+}
+
+
+function pushError(compilation) {
+  if (store.error) {
+    if (store.options.warn) {
+      compilation.warnings.push(store.error);
+    } else {
+      compilation.errors.push(store.error);
+    }
+
+    store.error = null;
+  }
+}
+
+
+function FlowFlowPlugin(options) {
+  store.options = merge(store.options, options);
+}
+
+FlowFlowPlugin.prototype.apply = function(compiler) {
+  compiler.plugin('run', checkFlowStatus);
+  compiler.plugin('watch-run', checkFlowStatus);
+
+  compiler.plugin('compilation', pushError);
+};
+
+module.exports = FlowFlowPlugin;
diff --git a/src/renderer/modal/modal.js b/src/renderer/modal/modal.js
index 39b32c067..a139698e1 100644
--- a/src/renderer/modal/modal.js
+++ b/src/renderer/modal/modal.js
@@ -1,18 +1,19 @@
 import React from "react";
+import PropTypes from "prop-types";
 import ReactModal from "react-modal";
 import Link from "component/link/index";
 import app from "app.js";
 
 export class Modal extends React.PureComponent {
   static propTypes = {
-    type: React.PropTypes.oneOf(["alert", "confirm", "custom"]),
-    overlay: React.PropTypes.bool,
-    onConfirmed: React.PropTypes.func,
-    onAborted: React.PropTypes.func,
-    confirmButtonLabel: React.PropTypes.string,
-    abortButtonLabel: React.PropTypes.string,
-    confirmButtonDisabled: React.PropTypes.bool,
-    abortButtonDisabled: React.PropTypes.bool,
+    type: PropTypes.oneOf(["alert", "confirm", "custom"]),
+    overlay: PropTypes.bool,
+    onConfirmed: PropTypes.func,
+    onAborted: PropTypes.func,
+    confirmButtonLabel: PropTypes.string,
+    abortButtonLabel: PropTypes.string,
+    confirmButtonDisabled: PropTypes.bool,
+    abortButtonDisabled: PropTypes.bool,
   };
 
   static defaultProps = {
@@ -64,8 +65,8 @@ export class Modal extends React.PureComponent {
 
 export class ExpandableModal extends React.PureComponent {
   static propTypes = {
-    expandButtonLabel: React.PropTypes.string,
-    extraContent: React.PropTypes.element,
+    expandButtonLabel: PropTypes.string,
+    extraContent: PropTypes.element,
   };
 
   static defaultProps = {
diff --git a/src/renderer/redux/actions/file_info.js b/src/renderer/redux/actions/file_info.js
index 84062ee23..89e50386f 100644
--- a/src/renderer/redux/actions/file_info.js
+++ b/src/renderer/redux/actions/file_info.js
@@ -102,8 +102,8 @@ export function doDeleteFile(outpoint, deleteFromComputer, abandonClaim) {
       const fileInfo = byOutpoint[outpoint];
 
       if (fileInfo) {
-        txid = fileInfo.outpoint.slice(0, -2);
-        nout = fileInfo.outpoint.slice(-1);
+        const txid = fileInfo.outpoint.slice(0, -2);
+        const nout = fileInfo.outpoint.slice(-1);
 
         dispatch(doAbandonClaim(txid, nout));
       }
diff --git a/src/renderer/redux/reducers/app.js b/src/renderer/redux/reducers/app.js
index b44e84ccb..b18062e0c 100644
--- a/src/renderer/redux/reducers/app.js
+++ b/src/renderer/redux/reducers/app.js
@@ -1,22 +1,60 @@
+// @flow
+
 import * as types from "constants/action_types";
 import * as modalTypes from "constants/modal_types";
 
 const { remote } = require("electron");
+
 const application = remote.app;
 const win = remote.BrowserWindow.getFocusedWindow();
 
 const reducers = {};
-const defaultState = {
+
+export type SnackBar = {
+  message: string,
+  linkText: string,
+  linkTarget: string,
+  isError: boolean,
+};
+export type AppState = {
+  isLoaded: boolean,
+  modal: ?string,
+  modalProps: mixed,
+  platform: string,
+  upgradeSkipped: boolean,
+  daemonVersionMatched: ?boolean,
+  daemonReady: boolean,
+  hasSignature: boolean,
+  badgeNumber: number,
+  volume: number,
+  downloadProgress: ?number,
+  upgradeDownloading: ?boolean,
+  upgradeDownloadComplete: ?boolean,
+  checkUpgradeTimer: ?number,
+  isUpgradeAvailable: ?boolean,
+  isUpgradeSkipped: ?boolean,
+  snackBar: ?SnackBar,
+};
+
+const defaultState: AppState = {
   isLoaded: false,
   modal: null,
   modalProps: {},
   platform: process.platform,
-  upgradeSkipped: sessionStorage.getItem("upgradeSkipped"),
+  upgradeSkipped: sessionStorage.getItem("upgradeSkipped") === "true",
   daemonVersionMatched: null,
   daemonReady: false,
   hasSignature: false,
   badgeNumber: 0,
-  volume: sessionStorage.getItem("volume") || 1,
+  volume: Number(sessionStorage.getItem("volume")) || 1,
+
+  downloadProgress: undefined,
+  upgradeDownloading: undefined,
+  upgradeDownloadComplete: undefined,
+  checkUpgradeTimer: undefined,
+  isUpgradeAvailable: undefined,
+  isUpgradeSkipped: undefined,
+  snackBar: undefined,
 };
 
 reducers[types.DAEMON_READY] = function(state, action) {
@@ -61,7 +99,7 @@ reducers[types.UPGRADE_DOWNLOAD_STARTED] = function(state, action) {
 };
 
 reducers[types.SKIP_UPGRADE] = function(state, action) {
-  sessionStorage.setItem("upgradeSkipped", true);
+  sessionStorage.setItem("upgradeSkipped", "true");
 
   return Object.assign({}, state, {
     isUpgradeSkipped: true,
@@ -164,7 +202,7 @@ reducers[types.VOLUME_CHANGED] = function(state, action) {
   });
 };
 
-export default function reducer(state = defaultState, action) {
+export default function reducer(state: AppState = defaultState, action: any) {
   const handler = reducers[action.type];
   if (handler) return handler(state, action);
   return state;
diff --git a/src/renderer/rewards.js b/src/renderer/rewards.js
index 2a30be2d3..1482fc1ca 100644
--- a/src/renderer/rewards.js
+++ b/src/renderer/rewards.js
@@ -22,7 +22,7 @@ function rewardMessage(type, amount) {
       amount
     ),
     many_downloads: __(
-      "You earned %s LBC for downloading some of the things.",
+      "You earned %s LBC for downloading a bunch of things.",
       amount
     ),
     first_publish: __(
@@ -33,6 +33,10 @@ function rewardMessage(type, amount) {
       "You earned %s LBC for watching a featured download.",
       amount
     ),
+     referral: __(
+      "You earned %s LBC for referring someone.",
+      amount
+    ),
   }[type];
 }