Hi, manan.modi.

You can create a recursive backend workflow, calling the next trigger to "current date and time + 7 days and create a conditional that don´t do it when “current date” > duedate.

If you need to show something to the user when he open the app, you can create a field in the table user with type “yes/no” and create an event "do when a condition is true current user “show´s field” is yes and the action show an element (to user)