diff --git a/README.md b/README.md
index 3fe1f7a..726d484 100644
--- a/README.md
+++ b/README.md
@@ -1,3 +1,38 @@
 # SheetJS + React Native Demo
 
-Complete Reproduction of <https://docs.sheetjs.com/docs/demos/mobile/reactnative#demo>
\ No newline at end of file
+Complete Reproduction of <https://docs.sheetjs.com/docs/demos/mobile/reactnative#demo>
+
+This branch (`RNBU`) demonstrates `react-native-blob-util`.
+
+## Installation
+
+1) Install dependencies:
+
+```bash
+npm i
+```
+
+### iOS
+
+2) (iOS only) link iOS project
+
+```bash
+cd ios; pod install; cd ..
+```
+
+3) run the development process:
+
+```bash
+npx react-native run-ios
+```
+
+### Android
+
+4) ensure Java 11 is the current version 
+
+5) run the development process:
+
+```bash
+npx react-native run-android
+```
+
diff --git a/index.js b/index.js
index 41a3fbc..9271e3c 100644
--- a/index.js
+++ b/index.js
@@ -4,6 +4,28 @@ import React, { Component } from 'react';
 import { AppRegistry, StyleSheet, Text, Button, Alert, Image, ScrollView } from 'react-native';
 import { Table, Row, Rows, TableWrapper } from 'react-native-table-component';
 
+import { read, write } from 'xlsx';
+import { pickSingle } from 'react-native-document-picker';
+import { Platform } from 'react-native';
+import RNFetchBlob from 'react-native-blob-util';
+
+async function pickAndParse() {
+  /* rn-fetch-blob / react-native-blob-util need a copy */
+  const f = await pickSingle({allowMultiSelection: false, copyTo: "documentDirectory", mode: "open" });
+  let path = f.fileCopyUri;
+  if (Platform.OS === 'ios') path = path.replace(/^.*\/Documents\//, RNFetchBlob.fs.dirs.DocumentDir + "/");
+  const res = await (await fetch(path)).arrayBuffer(); // RN >= 0.72
+  // const res = await RNFetchBlob.fs.readFile(path, 'ascii'); // RN < 0.72
+  return read(new Uint8Array(res), {type: 'buffer'});
+}
+
+async function writeWorkbook(wb) {
+  const wbout = write(wb, {type:'buffer', bookType:"xlsx"});
+  const file = RNFetchBlob.fs.dirs.DocumentDir + "/sheetjsw.xlsx";
+  await RNFetchBlob.fs.writeFile(file, Array.from(wbout), 'ascii');
+  return file;
+}
+
 const make_width = ws => {
   const aoa = utils.sheet_to_json(ws, {header:1}), res = [];
   aoa.forEach((r) => { r.forEach((c, C) => { res[C] = Math.max(res[C]||60, String(c).length * 10); }); });
diff --git a/ios/Podfile.lock b/ios/Podfile.lock
index 36ab9ee..d212e36 100644
--- a/ios/Podfile.lock
+++ b/ios/Podfile.lock
@@ -374,6 +374,8 @@ PODS:
   - React-jsinspector (0.72.1)
   - React-logger (0.72.1):
     - glog
+  - react-native-blob-util (0.17.1):
+    - React-Core
   - react-native-document-picker (8.2.0):
     - React-Core
   - React-NativeModulesApple (0.72.1):
@@ -537,6 +539,7 @@ DEPENDENCIES:
   - React-jsiexecutor (from `../node_modules/react-native/ReactCommon/jsiexecutor`)
   - React-jsinspector (from `../node_modules/react-native/ReactCommon/jsinspector`)
   - React-logger (from `../node_modules/react-native/ReactCommon/logger`)
+  - react-native-blob-util (from `../node_modules/react-native-blob-util`)
   - react-native-document-picker (from `../node_modules/react-native-document-picker`)
   - React-NativeModulesApple (from `../node_modules/react-native/ReactCommon/react/nativemodule/core/platform/ios`)
   - React-perflogger (from `../node_modules/react-native/ReactCommon/reactperflogger`)
@@ -618,6 +621,8 @@ EXTERNAL SOURCES:
     :path: "../node_modules/react-native/ReactCommon/jsinspector"
   React-logger:
     :path: "../node_modules/react-native/ReactCommon/logger"
+  react-native-blob-util:
+    :path: "../node_modules/react-native-blob-util"
   react-native-document-picker:
     :path: "../node_modules/react-native-document-picker"
   React-NativeModulesApple:
@@ -691,6 +696,7 @@ SPEC CHECKSUMS:
   React-jsiexecutor: 184eae1ecdedc7a083194bd9ff809c93f08fd34c
   React-jsinspector: d0b5bfd1085599265f4212034321e829bdf83cc0
   React-logger: b8103c9b04e707b50cdd2b1aeb382483900cbb37
+  react-native-blob-util: 4949dcc0dd5ee25fcb5abe0687f67fa3d5cdf05a
   react-native-document-picker: 495c444c0c773c6e83a5d91165890ecb1c0a399a
   React-NativeModulesApple: 4f31a812364443cee6ef768d256c594ad3b20f53
   React-perflogger: 3d501f34c8d4b10cb75f348e43591765788525ad
diff --git a/package.json b/package.json
index 82bae7e..bd76799 100644
--- a/package.json
+++ b/package.json
@@ -12,6 +12,7 @@
   "dependencies": {
     "react": "18.2.0",
     "react-native": "0.72.1",
+    "react-native-blob-util": "^0.17.1",
     "react-native-document-picker": "^8.2.0",
     "react-native-table-component": "^1.2.0",
     "xlsx": "https://cdn.sheetjs.com/xlsx-0.20.0/xlsx-0.20.0.tgz"