The next version of Steam Link for Android is now available as a beta build.

You can download it from Google Play by opting into the beta here:
https://play.google.com/apps/testing/com.valvesoftware.steamlink

Or downloading directly from Valve here:
https://media.steampowered.com/steamlink/android/latest/steamlink-android.apk

Changes in build 1.3.28.307:

• Added instructions for pairing the new Steam Controller
  
• Fixed several controller regressions introduced in the previous build

Changes in build 1.3.27.305:

• Added the ability to specify exact values for streaming bitrate, framerate, and resolution in the streaming settings
  
• Added support for the new Steam Controller connected via Bluetooth
  
• Fixed a hang in streaming settings if the microphone isn't available