Good alternative to YouTube Red

For all intents and purposes, ProTube accomplishes a lot of what YouTube Red does (for me at least).

Playback when the app is not in the foreground was what drew me to this app.

It does, at times, encounter issues where functionality will be inspired or will cease all together, but it usually when there is a change on YouTubes end and it is usually resolved with an update from the developer within a few days.

Christopher Steves about ProTube for YouTube, v2.5.9