I'm 40 years old, starting working with the Simply Piano app a few months ago and spend about 30 minutes to an hour each day practicing. I have zero prior musical experience. I think a piano teacher would probably be an excellent investment, my daughter started piano around the same time with a teacher and she is progressing slower, but I can see that she already has a much more solid base than I do and will learn to play much better than I likely ever will. However I'm not in this to learn in any serious way, just to noodle around and play songs that I like and I find that working with an app that gives instant feedback is a relaxed and low pressure way to do that.