Startup Idea : Forced language study

Hello creative people, Recently I have come up with an idea to create an app that will make people (studying languages) learn new words every time they unlock their moblie phones. Usually, when I download an app for learning a language, I visit it once or twice and then because of having no time or some other reason I just forget about it. So I thought what if the app will visit you by itself every time you unlock your phone. It can be a multiple choice, for instance, and if you don't know the right definition and answer it wrong, the app will offer you to ask the same question later, and if you tick it, then next time you unlock the phone, the same question will pop up again and this time you will surely remember the right definition,if not, then do it again. Maybe it will be annoying sometimes but who said learning is all about pleasure:)) I just need your opinion about this and will be happy to hear from you:) Sincerely, Ashot