How to collect email and update weekly contest winners in app?

I have come across an app that runs a weekly contest. collect emails, numbers and announces the winner after a week in the app and that app is I think made in kodular.
Any suggestions on how to achieve that?

Use textboxes button and a database to get and store data from users…
BTW what kind of app is this? What are the basis of selecting winner? What is weekly contest?

I am trying to add a feature where in if you share the app you get prizes, cash, etc.

any inputs on how I can achieve this ?

man i already told a way. Many big companies use the same way