Assalamu ailaikum .
I wanted to give some feedback based on my experience.
1. When I ask for a dua , I can select the make dua option for my one too.
2. When people say they are making duas , there is no check if they are really doing so . Rather , you can prompt a dialogbox and instruct the user how to properly make a dua and then grant his/her request.
3. Currently the user can only take help of this app to the make prayers , if you could use gamification or challenges to help the user better .
4. There can be a forum to discuss matters about.
May peace be upon you .