Sounds like a great idea! I think access to services is a huge problem so having something like this might help in the interim/ for low intensity purposes. It can be really difficult to leave the house/make appointments and iCBT as part of IAPT in the UK seems to be successful. Whereas I agree with some of the other comments that time away from screens and being outdoors might be more helpful – listing gratitudes as suggested in your app has also been shown to improve mental health. We probably all know we should get out more/ go to the gym to make ourselves feel better, but doing it isn’t always easy. Having an app might be an easier way or at least a starting point to feeling better. Journaling in morning or eve to set goals/ intentions for the day could be a neat feature for it too.

Germany's health insurances also pay for similar products (e.g. selfapy) and I've heard good things. They include CBT style homework and journaling - but are limited to 6 weeks (i think?) and offer a weekly check in with an assistant psychologist - have you considered adding check ins? I’m also not quite clear on whether its aimed at any “diagnosis” in particular (anxiety/depression) or general low intensity work?

Best of luck!