How long should I continue using the app?

As long as you continue to find it helpful. Breaking unhealthy eating habits and establishing healthy eating patterns takes time. Shifting to time-restricted eating or intermittent fasting (if that is what you are attempting) takes even longer to feel entirely natural. Using the app for 6 months or even longer is probably realistic and that's precisely why we decided not to make this a subscription-based app. We want you to keep going and we don't want to penalize you financially because of the fact that it takes time to form new eating habits. 

We think learning how to eat differently and to keep the new patterns going is as challenging as learning a new language. You can catch on to a few phrases quickly, but to become fluent, to be able to think in a foreign language and have it feel natural, you need a lot of practice and more than a year of immersion. That's what it's like to trade in old eating habits in our super tempting food environment to become "fluent" in healthy eating. So, the answer is: Keep using the app and practicing mindful eating daily for as long as it takes -- usually a year or so-- until you are a fluent healthy eater.