iPhoto app on Mac

[MacCult62]

I recently migrated all my files from MBA to MBP. I just want to keep the iPhoto app on the MBA, but how do I delete it on the MBP? Same question for the iMovie app. I want to delete them because I just read it is not a good idea to have the same photo library on 2 different Macs.
The problem that arises is that I updated iPhoto on MBA (after the migration) but I can't do it on the MBP. I get the message on MBP that I need to sign in with another account that was apparently used to purchase iPhoto in first place. But I have been using the same account on both MBA and MBP.