How to check previous version app already installed in iOS Device?

it assumes very simple question but its typical problem for me .

I have a live paid iOS app in App Store . I want to update it in my phone with new Sqlite . I want test some scenario for that I want installed update from my Xcode in free. How can i update app installed from App store by Xcode as i have new code of that app. in my live app there in no USERDEFAULTS to store current version.i can code in new app.

How to delete previously used sqlite and installed new app free if already buy that app.

Thanx for reading. guide me if any understand it and any idea about it. Thank in advacnce