There are 2 repositories under leanback-launcher topic.
This is a leanback style tv launcher(minSdkVersion 17)
Simple helper application to allow custom launchers on Amazon Fire TV devices.
MDZ-18-AA internationalization, gapps, gappsTV. Patches for working Xiaomi services on customized system
How to develop an application on Android TV? 📺
Easy shortcuts to most-used settings on Xiaomi Mi TV (Global). Android version: 9 (Pie)
Simple Leanback style TV launcher