Smart YouTube TV is a third-party, open-source YouTube client specifically designed for Android TV boxes and smart TVs. It is a popular solution for older devices because it supports legacy operating systems starting from Android 4.2 (Jelly Bean) and higher, making it compatible with Android 4.4.2 (KitKat). Key Features

No sound over Bluetooth

• Fix: Android 4.4.2 has Bluetooth audio latency issues. Use wired headphones or install SoundAbout (legacy version) to force audio routing.

Smart YouTube TV 6.17.739: This is widely considered the most stable "final" version for older Android versions. It supports 1080p and 4K resolutions and works without Google Play Services.

Designed with a small footprint to run smoothly on limited memory. How to Install on Your Old Smart TV