Only wanted to install an app to the iPhone using another iTunes than it syncs to… turns out that warning that says all applications will be replaced is actually true: it promptly deleted all the applications previously installed on my phone. (The test devices we have do not behave like this for some reason.)
What can you do if this happens? iCloud backups can be used to painlessly restore a phone to its original state, here’s how (please note that WiFi access is needed):
- Go to Settings > General > Reset and choose Erase All Content and Settings. This is equivalent to a factory reset.
- Go through the steps of the Setup Assistant and enter your Apple ID.
- Choose a backup to restore to.
First the settings are restored, then the phone reboots and begins to download all the applications, their data, the photo stream, everything, Really it’s equally as magical as Time Machine: when it finishes the phone is exactly in the same state as it was during the backup. Mine even got the alarm for that morning switched on.