Nice content but user experience with an Android smartphone is not so good. If I want to start a video or navigate between lesson there's always a variable lag of time. Theres not enough space on the screen to avoid pressing buttons we don't want to press, looping is not precise and all operation is charge by a lot of waste of time to navigate. All fonction aviable (keyboard piano roll, transcription, subtitles, loop fonction ) présent very often bugs and they don't work correctly. Videos too, they are sometimes very long and the good information need to be extrapolated from a lot of words and space fillers. I suggest to invest on a platform "mobile friendly", a lighter one, that allow to navigate quickly and without waste of time. All fonction like piano roll, synchronized slice sheet musique, loop and so on must be revised to remove bugs and problem, they slow down a lot all the system without advantages. I use a lot YouTube, I pay for removing ads, it's fast, audio and video have an enough good quality to profit completely of the content. There's not fancy option that's true, and looping is almost impossible for z lack of precision. I hope my ideas are clear, if you want we can discuss again about these subjects. Best regards Stefano Schipani