Basic instructions to build the PlayTorch app

app/README.md

@@ -2,6 +2,79 @@
 
 This folder contains the code to build the PlayTorch app.
 
+## Development
+
+Build the PlayTorch requires the React Native development environment to be set up. If you haven't done this before, follow the steps on the [React Native Environment Setup](https://reactnative.dev/docs/environment-setup) steps on the React Native website.
+
+### Navigate to PlayTorch app directory
+
+Navigate to the PlayTorch app directory.
+
+```
+cd app
+```
+
+Note: It's the same directory as this `README.md`. You can skip this step if you are already in this directory.
+
+### Install app dependencies
+
+The PlayTorch app is a Expo prebuild app. It uses `yarn` to manage app dependencies. Use the following command to install all dependencies:
+
+```
+yarn
+```
+
+### Run app on Android
+
+#### Change gradle.properties
+
+Update the Gradle `distributionUrl` from
+
+```
+distributionUrl=../../../../../ci/gradle-7.5.1-all.zip
+```
+
+to
+
+```
+distributionUrl=https\://services.gradle.org/distributions/gradle-7.5.1-all.zip
+```
+
+Or alternatively, apply the following patch:
+
+```diff 
+diff --git a/app/android/gradle/wrapper/gradle-wrapper.properties b/app/android/gradle/wrapper/gradle-wrapper.properties
+--- a/app/android/gradle/wrapper/gradle-wrapper.properties
++++ b/app/android/gradle/wrapper/gradle-wrapper.properties
+@@ -1,5 +1,5 @@
+ distributionBase=GRADLE_USER_HOME
+ distributionPath=wrapper/dists
+-distributionUrl=../../../../../ci/gradle-7.5.1-all.zip
++distributionUrl=https\://services.gradle.org/distributions/gradle-7.5.1-all.zip
+ zipStoreBase=GRADLE_USER_HOME
+ zipStorePath=wrapper/dists
+```
+
+Build the app for Android
+
+```
+yarn android
+```
+
+### Run app on iOS
+
+Install CocoaPod dependencies
+
+```
+(cd ios && pod install)
+```
+
+Build the app for iOS
+
+```
+yarn ios
+```
+
 ## Attribution
 
 The following pages contain the attribution notices for third party software that may be contained in portions of this product: