I want to create an app with features blocking certain content on the internet and iPhone. Before I start coding the app I wanted to see if it's possible with the user's permission to create an app that can't be deleted until after 3 days/timer. Is it possible to create an app with this feature and put it on the Apple Store or do they not allow this?
There's no supported way for you to locking apps to devices for limited time periods with the APIs currently available. If you'd like us to consider adding the necessary functionality, please file an enhancement request using Feedback Assistant. Once you file the request, please post the FB number here.
If you're not familiar with how to file enhancement requests, take a look at Bug Reporting: How and Why?