diff --git a/.gitignore b/.gitignore
index 828891254..ddc8fcab6 100644
--- a/.gitignore
+++ b/.gitignore
@@ -31,48 +31,3 @@ vcpkg
 # Visual Studio Code
 .vscode/
 
-# Firestore testapp
-firestore/testapp/**/*.dll
-firestore/testapp/**/*.pdb
-firestore/testapp/**/*.bundle
-firestore/testapp/**/*.meta
-
-firestore/testapp/Assets/Plugins
-firestore/testapp/Assets/StreamingAssets
-firestore/testapp/Assets/Editor Default Resources
-firestore/testapp/Assets/ExternalDependencyManager
-firestore/testapp/Assets/Firebase/Editor/*.xml
-firestore/testapp/Assets/Firebase/Editor/*.txt
-firestore/testapp/Assets/Firebase/Editor/*.exe
-firestore/testapp/Assets/Firebase/Editor/*.py
-firestore/testapp/Assets/Firebase/Sample/AutomatedTestRunner.cs
-firestore/testapp/Assets/Firebase/Sample/ftl_testapp_files
-firestore/testapp/Assets/Firebase/m2repository
-
-firestore/testapp/Library
-firestore/testapp/Logs
-firestore/testapp/Packages
-firestore/testapp/Temp
-firestore/testapp/UserSettings
-firestore/testapp/android_BackUpThisFolder_ButDontShipItWithYourGame
-firestore/testapp/ios
-firestore/testapp/macos.app/Contents
-firestore/testapp/obj/Debug
-firestore/testapp/Assembly-CSharp-Editor.csproj
-firestore/testapp/Assembly-CSharp-firstpass.csproj
-firestore/testapp/Assembly-CSharp.csproj
-firestore/testapp/Tests.csproj
-firestore/testapp/android.apk
-firestore/testapp/android_mapping.txt
-firestore/testapp/testapp.sln
-
-firestore/testapp/ProjectSettings/AndroidResolverDependencies.xml
-firestore/testapp/ProjectSettings/GvhProjectSettings.xml
-firestore/testapp/ProjectSettings/MemorySettings.asset
-firestore/testapp/ProjectSettings/PackageManagerSettings.asset
-firestore/testapp/ProjectSettings/PresetManager.asset
-firestore/testapp/ProjectSettings/TimelineSettings.asset
-firestore/testapp/ProjectSettings/VFXManager.asset
-firestore/testapp/ProjectSettings/VersionControlSettings.asset
-firestore/testapp/ProjectSettings/XRSettings.asset
-firestore/testapp/ProjectSettings/boot.config
\ No newline at end of file
diff --git a/firestore/.gitignore b/firestore/.gitignore
new file mode 100644
index 000000000..21fb2dcb6
--- /dev/null
+++ b/firestore/.gitignore
@@ -0,0 +1,44 @@
+testapp/**/*.dll
+testapp/**/*.pdb
+testapp/**/*.bundle
+testapp/**/*.meta
+
+testapp/Assets/Plugins
+testapp/Assets/StreamingAssets
+testapp/Assets/Editor Default Resources
+testapp/Assets/ExternalDependencyManager
+testapp/Assets/Firebase/Editor/*.xml
+testapp/Assets/Firebase/Editor/*.txt
+testapp/Assets/Firebase/Editor/*.exe
+testapp/Assets/Firebase/Editor/*.py
+testapp/Assets/Firebase/Sample/AutomatedTestRunner.cs
+testapp/Assets/Firebase/Sample/ftl_testapp_files
+testapp/Assets/Firebase/m2repository
+
+testapp/Library
+testapp/Logs
+testapp/Packages
+testapp/Temp
+testapp/UserSettings
+testapp/android_BackUpThisFolder_ButDontShipItWithYourGame
+testapp/ios
+testapp/macos.app/Contents
+testapp/obj/Debug
+testapp/Assembly-CSharp-Editor.csproj
+testapp/Assembly-CSharp-firstpass.csproj
+testapp/Assembly-CSharp.csproj
+testapp/Tests.csproj
+testapp/android.apk
+testapp/android_mapping.txt
+testapp/testapp.sln
+
+testapp/ProjectSettings/AndroidResolverDependencies.xml
+testapp/ProjectSettings/GvhProjectSettings.xml
+testapp/ProjectSettings/MemorySettings.asset
+testapp/ProjectSettings/PackageManagerSettings.asset
+testapp/ProjectSettings/PresetManager.asset
+testapp/ProjectSettings/TimelineSettings.asset
+testapp/ProjectSettings/VFXManager.asset
+testapp/ProjectSettings/VersionControlSettings.asset
+testapp/ProjectSettings/XRSettings.asset
+testapp/ProjectSettings/boot.config
diff --git a/firestore/CONTRIBUTING.md b/firestore/CONTRIBUTING.md
index 5d52ebf3f..919a0c6f3 100644
--- a/firestore/CONTRIBUTING.md
+++ b/firestore/CONTRIBUTING.md
@@ -6,11 +6,12 @@ the SDK, targeting desktop/Android/iOS.
 # Prerequisites
 
 Building the Unity SDK requires building the underlying C++ SDK. Refer to
-[][this doc] for what the prerequisites are.
+[https://github.com/firebase/firebase-cpp-sdk#prerequisites][this doc] for 
+what the prerequisites are.
 
 On top of above, you also need Unity installed (obviously). If you use an
-apple silicon machine as host, be sure to install the right version of
-Unity!
+apple silicon machine as host, be sure to install Unity for Apple Silicon,
+otherwise Unity will report missing binaries when you try to run the Testapp.
 
 # Building Firestore Unity SDK
 
@@ -33,6 +34,11 @@ python scripts/build_scripts/build_zips.py -platform=android -targets=auth -targ
 # Building for iOS. Incremental build for iOS is broken, so we use clean_build here.
 python scripts/build_scripts/build_zips.py -platform=android -targets=auth -targets=firestore -use_boringssl -clean_build
 
+# Build with OPENSSL: above use boringssl by default, which could add to build time, you can
+# use a binary OPENSSL if you want to, by specifying the location with a ENV Variable.
+OPENSSL_ROOT_DIR=/opt/homebrew/opt/openssl@1.1 python scripts/build_scripts/build_zips.py -platform=macos -targets=auth -targets=firestore
+
+
 # Other supported platforms are tvos,linux,windows
 ```
 
@@ -63,11 +69,12 @@ able to run this scene which in turn runs all integration tests for Firestore.
 
 # Running Firestore Android TestApp
 
-You *probably* need to use `IL2CPP` as scripting backend instead of `Mono` for Android. To do this,
-you can go to `Edit->Project Setting->Player->Android->Scripting Backend` and select `IL2CPP`.
+*Apple Silicon Unity user*: you need to use `IL2CPP` as scripting backend instead of `Mono` for Android, otherwise you
+cannot target for `ARM64`. To do this, you can go to 
+`Edit->Project Setting->Player->Android->Scripting Backend` and select `IL2CPP`, and also select `Arm64` as target.
 
 You also need to turn on `minification` under on the same setting page, by turning on `R8` under `publish
-settings`.
+settings`. Otherwise you could see build error from task `minifyDebugWithProguard`.
 
 To run the Android testapp, go to `File->Build Settings`, select `Android` then click `Switch Platform`. After
 assets are loaded, click `Build and Run`.