Hi Lepule, that's a great question! There's really two separate things to consider here in your question: (1) building retention, and (2) converting a user to payment. Let's start with retention. I would start with these two questions: - Is the problem you are solving recurring? Meaning is the problem something that the user needs to address weekly, or daily? For example, filing your taxes is a one-time a year occurrence in the U.S. However, calorie tracking is something that someone who is trying to lose weight would be doing daily. Tools that are tied to a habit or routine are good to anchor around. - Do you make your value to the user immediately clear? If a user can't get a helpful result within a few minutes, you are going to lose them. If you have those two pieces established, then you can start thinking about things like gamifying the experience, e.g. streaks, reminders, and progress views. Also, as users continue to return to your app, you could begin personalizing the content based on their user history. However, I would strongly advise against investing in anything here until you've really nailed down the first two points above. Converting a user to payment is something that can start once you are solving a problem really well. If you are able to build up a loyal user base, you could then introduce a more premium feature that you gate behind a paid tier.