I don't want to erase all my existing apps. I just want to install the .ipa file and KEEP all my existing apps. However iTunes says
Are you sure you want to sync apps?
All existing apps and their data on
the iPhone "Simon Strandgaard's
iPhone" will be replaced with apps
from this iTunes library.
I really don't want to click the "Sync Apps" button.
I could go home and open iTunes on my own computer, but I'm at my friends place. How to do get the .ipa on my iPhone?
Best Answer
You can use the iPhone Configuration Utility to side-load apps onto an iOS device without 'syncing' and erasing your current content.
Config Utility for Mac
Config Utility for Windows
Keep in mind, though, that this will only work if the app is correctly codesigned and the device is correctly provisioned.