Improve docs

Author: MartinBraquet

android/README.md

@@ -116,12 +116,19 @@ npx cap sync android
 
 ### Load from site
 
-During local development, open Android Studio project and run the app on an emulator or your physical device. Note that right now you can't use a physical device for the local web version (`10.0.2.2:3000 time out` )
+During local development, open Android Studio project and run the app on an emulator or your physical device. 
 
+To use an emulator:
 ```
 npx cap open android
 ```
 
+To use a physical device for the local web version, you need your mobile and computer to be on the same network / Wi-Fi and point the URL (`LOCAL_BACKEND_DOMAIN` in the code) to your computer IP address (for example, `192.168.1.3:3000`). You also need to set
+```
+export NEXT_PUBLIC_WEBVIEW_DEV_PHONE=1
+```
+Then adb install the app your phone (or simply run it from Android Studio on your phone) and the app should be loading content directly from the local code on your computer. You can make changes in the code and it will refresh instantly on the phone.
+
 Building the Application:
 1. Open Android Studio.
 2. Click on "Open an existing Android Studio project".
@@ -175,6 +182,10 @@ adb install -r app/build/outputs/apk/debug/app-debug.apk
    ./gradlew assembleRelease
    ```
 
+### Release on App Stores
+
+To release on the app stores, you need to submit the .aab files, which are not signed, instead of APK. Google or Apple will then sign it with their own key.
+
 ---
 ## 9. Debugging
 
@@ -362,3 +373,17 @@ await admin.messaging().send(message)
 ```
 
 ---
+
+## Deep link / custom scheme
+
+A **custom scheme** is a URL protocol that your app owns.
+Example:
+
+```
+com.compassconnections.app://auth
+```
+
+
+When Android (or iOS) sees a redirect to one of these URLs, it **launches your app** and passes it the URL data. It's useful to open links in the app instead of the browser. For example, if there's a link to Compass on Discord and we click on it on a mobile device that has the app, we want the link to open in the app instead of the browser.
+
+You register this scheme in your `AndroidManifest.xml` so Android knows which app handles it.