HOWEVER.
Because it's just an app with videos, it's really up to you to learn proper form and execute it each time. Additionally, the app doesn't know your limitations, so take your pain seriously.
I hurt my knees squatting a couple years ago, and recently hurt my lower back deadlifting. It sucks, and I'm crossing my fingers that there's no permanent damage.
If I were to go back in time, I'd force myself to book yearly or twice-yearly sessions with a physical trainer who can check you on your form, particularly when I first got started.