A great idea but too expensive
The idea behind the app is amazing and I could see myself improving with the practice. I am a beginner with an electric guitar though I have regular practice with an acoustic. This is simply a tool in addition to regular development of one’s guitar skills. I regret buying it for almost €18. I do not think it has the value to justify the price. Maybe I will come back to the app later as I do find it useful to make sure you are hitting the intervals well. But for now I would rather put the money towards lessons and would only keep the app if it were between a third to half of the current price