diff --git a/README.md b/README.md
index 3fe1f7a..a532498 100644
--- a/README.md
+++ b/README.md
@@ -1,3 +1,37 @@
 # 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 (`RNFS`) demonstrates `react-native-fs`.
+
+## 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..d72474f 100644
--- a/index.js
+++ b/index.js
@@ -4,6 +4,23 @@ 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 { writeFile, readFile, DocumentDirectoryPath } from 'react-native-fs';
+
+async function pickAndParse() {
+  const f = await pickSingle({allowMultiSelection: false, copyTo: "cachesDirectory", mode: "open" });
+  const bstr = await readFile(f.fileCopyUri, 'ascii');
+  return read(bstr, {type:'binary'});
+}
+
+async function writeWorkbook(wb) {
+  const wbout = write(wb, {type:'binary', bookType:"xlsx"});
+  const file = DocumentDirectoryPath + "/sheetjsw.xlsx";
+  await writeFile(file, 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..a509af3 100644
--- a/ios/Podfile.lock
+++ b/ios/Podfile.lock
@@ -374,7 +374,7 @@ PODS:
   - React-jsinspector (0.72.1)
   - React-logger (0.72.1):
     - glog
-  - react-native-document-picker (8.2.0):
+  - react-native-document-picker (8.2.1):
     - React-Core
   - React-NativeModulesApple (0.72.1):
     - hermes-engine
@@ -486,6 +486,8 @@ PODS:
     - React-jsi (= 0.72.1)
     - React-logger (= 0.72.1)
     - React-perflogger (= 0.72.1)
+  - RNFS (2.20.0):
+    - React-Core
   - SocketRocket (0.6.1)
   - Yoga (1.14.0)
   - YogaKit (1.18.1):
@@ -555,6 +557,7 @@ DEPENDENCIES:
   - React-runtimescheduler (from `../node_modules/react-native/ReactCommon/react/renderer/runtimescheduler`)
   - React-utils (from `../node_modules/react-native/ReactCommon/react/utils`)
   - ReactCommon/turbomodule/core (from `../node_modules/react-native/ReactCommon`)
+  - RNFS (from `../node_modules/react-native-fs`)
   - Yoga (from `../node_modules/react-native/ReactCommon/yoga`)
 
 SPEC REPOS:
@@ -654,6 +657,8 @@ EXTERNAL SOURCES:
     :path: "../node_modules/react-native/ReactCommon/react/utils"
   ReactCommon:
     :path: "../node_modules/react-native/ReactCommon"
+  RNFS:
+    :path: "../node_modules/react-native-fs"
   Yoga:
     :path: "../node_modules/react-native/ReactCommon/yoga"
 
@@ -691,7 +696,7 @@ SPEC CHECKSUMS:
   React-jsiexecutor: 184eae1ecdedc7a083194bd9ff809c93f08fd34c
   React-jsinspector: d0b5bfd1085599265f4212034321e829bdf83cc0
   React-logger: b8103c9b04e707b50cdd2b1aeb382483900cbb37
-  react-native-document-picker: 495c444c0c773c6e83a5d91165890ecb1c0a399a
+  react-native-document-picker: 69ca2094d8780cfc1e7e613894d15290fdc54bba
   React-NativeModulesApple: 4f31a812364443cee6ef768d256c594ad3b20f53
   React-perflogger: 3d501f34c8d4b10cb75f348e43591765788525ad
   React-RCTActionSheet: f5335572c979198c0c3daff67b07bd1ad8370c1d
@@ -709,6 +714,7 @@ SPEC CHECKSUMS:
   React-runtimescheduler: 67707a955b9ecc628cc38bdc721fbc498910f0fd
   React-utils: 0a70ea97d4e2749f336b450c082905be1d389435
   ReactCommon: e593d19c9e271a6da4d0bd7f13b28cfeae5d164b
+  RNFS: 4ac0f0ea233904cb798630b3c077808c06931688
   SocketRocket: f32cd54efbe0f095c4d7594881e52619cfe80b17
   Yoga: 65286bb6a07edce5e4fe8c90774da977ae8fc009
   YogaKit: f782866e155069a2cca2517aafea43200b01fd5a
diff --git a/package.json b/package.json
index 82bae7e..5b5543c 100644
--- a/package.json
+++ b/package.json
@@ -13,6 +13,7 @@
     "react": "18.2.0",
     "react-native": "0.72.1",
     "react-native-document-picker": "^8.2.0",
+    "react-native-fs": "^2.20.0",
     "react-native-table-component": "^1.2.0",
     "xlsx": "https://cdn.sheetjs.com/xlsx-0.20.0/xlsx-0.20.0.tgz"
   },