I've been using MyKaraoke Video on and off for months. It's been extremely easy to make quick videos - the prices are pretty low, as well. I've basically just paid for the month on and off whenever I need to make new videos. Rather notably, I've noticed that any time I've tried making a video with something a little more creative, such as two languages displayed at once, the app developers will suddenly add it as a new feature. The app is clearly in active development and it's improved a lot in a short time!