diff --git a/App.test.js b/App.test.js
index 691f6fef5..2be770bd8 100644
--- a/App.test.js
+++ b/App.test.js
@@ -4,6 +4,7 @@ import { LegacyWallet } from './class';
 import renderer from 'react-test-renderer';
 import App from './App';
 import Settings from './screen/settings';
+import Selftest from './screen/selftest';
 import { BlueHeader } from './BlueComponents';
 let assert = require('assert');
 jest.mock('react-native-qrcode', () => 'Video');
@@ -35,3 +36,27 @@ it('Settings work', () => {
   const rendered = renderer.create(<Settings />).toJSON();
   expect(rendered).toBeTruthy();
 });
+
+it('Selftest work', () => {
+  const component = renderer.create(<Selftest />);
+  const root = component.root;
+  const rendered = component.toJSON();
+  expect(rendered).toBeTruthy();
+  // console.log((root.findAllByType('Text')[0].props));
+
+  let okFound = false;
+  let allTests = [];
+  for (var v of root.findAllByType('Text')) {
+    let text = v.props.children;
+    if (text.join) {
+      text = text.join('');
+    }
+    if (text === 'OK') {
+      okFound = true;
+    }
+    allTests.push(text);
+    // console.log(text);
+  }
+
+  assert.ok(okFound, 'OK not found. Got: ' + allTests.join('; '));
+});
diff --git a/screen/selftest.js b/screen/selftest.js
new file mode 100644
index 000000000..428cbd1eb
--- /dev/null
+++ b/screen/selftest.js
@@ -0,0 +1,171 @@
+import React, { Component } from 'react';
+import { ScrollView, View } from 'react-native';
+import Ionicons from 'react-native-vector-icons/Ionicons';
+import {
+  BlueLoading,
+  BlueSpacing20,
+  SafeBlueArea,
+  BlueCard,
+  BlueText,
+  BlueHeader,
+} from '../BlueComponents';
+import { SegwitP2SHWallet, LegacyWallet } from '../class';
+let BlueApp = require('../BlueApp');
+let BigNumber = require('bignumber.js');
+
+export default class Selftest extends Component {
+  static navigationOptions = {
+    tabBarLabel: 'Self test',
+    tabBarIcon: ({ tintColor, focused }) => (
+      <Ionicons
+        name={focused ? 'ios-settings' : 'ios-settings-outline'}
+        size={26}
+        style={{ color: tintColor }}
+      />
+    ),
+  };
+
+  constructor(props) {
+    super(props);
+    this.state = {
+      isLoading: true,
+    };
+  }
+
+  async componentDidMount() {
+    let errorMessage = '';
+    let isOk = true;
+
+    let uniqs = {};
+    let w = new SegwitP2SHWallet();
+    for (let c = 0; c < 10000; c++) {
+      w.generate();
+      if (uniqs[w.getSecret()]) {
+        errorMessage += 'failed to generate unique private key; ';
+        isOk = false;
+        break;
+      }
+      uniqs[w.getSecret()] = 1;
+    }
+
+    //
+
+    let l = new LegacyWallet();
+    l.setSecret('Kxr9tQED9H44gCmp6HAdmemAzU3n84H3dGkuWTKvE23JgHMW8gct');
+    if (l.getAddress() !== '19AAjaTUbRjQCMuVczepkoPswiZRhjtg31') {
+      errorMessage += 'failed to generate legacy address from WIF; ';
+      isOk = false;
+    }
+
+    //
+
+    l = new SegwitP2SHWallet();
+    l.setSecret('Kxr9tQED9H44gCmp6HAdmemAzU3n84H3dGkuWTKvE23JgHMW8gct');
+    if (l.getAddress() !== '34AgLJhwXrvmkZS1o5TrcdeevMt22Nar53') {
+      errorMessage += 'failed to generate segwit P2SH address from WIF; ';
+      isOk = false;
+    }
+
+    //
+
+    let utxo = [
+      {
+        tx_hash:
+          '0f5eea78fb19e72b55bd119252ff29fc16c503d0e956a9c1b5b2ab0e95e0c323',
+        block_height: 514991,
+        tx_input_n: -1,
+        tx_output_n: 2,
+        value: 546,
+        ref_balance: 546,
+        spent: false,
+        confirmations: 9,
+        confirmed: '2018-03-24T18:13:36Z',
+        double_spend: false,
+      },
+    ];
+
+    let tx = l.createTx(
+      utxo,
+      0.001,
+      0.0001,
+      '1QHf8Gp3wfmFiSdEX4FtrssCGR68diN1cj',
+    );
+    let bitcoin = require('bitcoinjs-lib');
+    let txDecoded = bitcoin.Transaction.fromHex(tx);
+    let txid = txDecoded.getId();
+
+    if (
+      txid !==
+      '110f51d28d585e922adbf701cba802e549b8fe3a53fa5d62426ab42549c9b6de'
+    ) {
+      errorMessage += 'created txid doesnt match; ';
+      isOk = false;
+    }
+    if (
+      tx !==
+      '0100000000010123c3e0950eabb2b5c1a956e9d003c516fc29ff529211bd552be719fb78ea5e0f0200000017160014597ce022baa887799951e0496c769d9cc0c759dc0000000001a0860100000000001976a914ff715fb722cb10646d80709aeac7f2f4ee00278f88ac0247304402202507d6b05ab19c7fdee217e97fddab80d481d7b2a103c00cecfc634bf897188d02205fa62ad413b6e441f99f94d7d8f9cd4ba51a1d928cbdec6873fa915236dd6d92012103aea0dfd576151cb399347aa6732f8fdf027b9ea3ea2e65fb754803f776e0a50900000000'
+    ) {
+      errorMessage += 'created tx hex doesnt match; ';
+      isOk = false;
+    }
+
+    let feeSatoshi = new BigNumber(0.0001);
+    feeSatoshi = feeSatoshi.mul(100000000);
+    let satoshiPerByte = feeSatoshi.div(Math.round(tx.length / 2));
+    satoshiPerByte = Math.round(satoshiPerByte.toString(10));
+
+    if (satoshiPerByte !== 46) {
+      errorMessage += 'created tx satoshiPerByte doesnt match; ';
+      isOk = false;
+    }
+
+    //
+
+    this.setState({
+      isLoading: false,
+      isOk,
+      errorMessage,
+    });
+  }
+
+  render() {
+    if (this.state.isLoading) {
+      return <BlueLoading />;
+    }
+
+    return (
+      <SafeBlueArea forceInset={{ horizontal: 'always' }} style={{ flex: 1 }}>
+        <BlueHeader
+          backgroundColor={BlueApp.settings.brandingColor}
+          centerComponent={{
+            text: 'Self test',
+            style: { color: '#fff', fontSize: 25 },
+          }}
+        />
+        <BlueCard>
+          <ScrollView maxHeight={450}>
+            <BlueSpacing20 />
+
+            {(() => {
+              if (this.state.isOk) {
+                return (
+                  <View style={{ alignItems: 'center' }}>
+                    <BlueText h4>OK</BlueText>
+                  </View>
+                );
+              } else {
+                return (
+                  <View style={{ alignItems: 'center' }}>
+                    <BlueText h4>error: {this.state.errorMessage}</BlueText>
+                  </View>
+                );
+              }
+            })()}
+          </ScrollView>
+        </BlueCard>
+      </SafeBlueArea>
+    );
+  }
+}
+
+Selftest.propTypes = {};