Is there any good android video editing software that allows overlay of videos?

Ok so I know that I should just use a computer but due to other reasons my computer is broken. I just need a good app that allows overlay (or if you call it overlap) of videos. I needs to be able to support unlimited video lengths, HD quality and free. Andoid only and if there are any other apps thatcome close you should still post. I need this for making minecraft gaming videos on my Youtube channel.