To the OP, I just want to add that as a software developer, I know that it costs a whole lot of money to develop and maintain these apps. To give you some perspective, to implement a requested feature in the app, it might cost GuitarTricks 5 to 10k. Multiply that by 2 if you want to implement it in both iOS and Android. Oh and the website cost is separate as well. Add that to the licensing fees and the instructor royalties and you can start to see why they don't have an app as fancy as soemthing Google might release. I'm sure they'll implement requested features as they can afford it.