Facebook 3.0 was heralded as a long-awaited, must-have upgrade on the iPhone, but the initial 3.0 release left many of our readers with a bad feeling. CNET users sent in numerous complaints about the app frequently crashing and wanted to know how to downgrade to the previous version.
Facebook quickly released updates and the app has since stabilized, but you should know that regardless of how big or popular an app is, you can usually roll it back following this tutorial.
If you want to downgrade an iPhone app, you must have a copy of the older version of the app, or this how-to won't work.
We recommend that you make frequent backups of your ~/Music/iTunes/Mobile Applications/ folder, which is located in your home directory (represented by the ~) on the Mac. PC users will find the same folder located at C:\Documents and Settings\username\My Documents\My Music\iTunes/Mobile Applications. These are the folders that iTunes uses to store all app files in your iTunes Library. The app files themselves are represented by file names ending in .ipa. If you keep frequent daily backups, you should always have older versions of your apps available.
How to downgrade an app
Take the following steps to easily downgrade to an older version of any iPhone or iPod Touch app:
Delete the app from your iPhone or iPod Touch
1. Locate the icon of the app you want to delete on the home screen. Tap and press down on its icon until the icons on the home screen start to jiggle. Next tap the X icon in the upper left corner of the app icon. Finally, tap Delete when the prompt pops up.
Delete the app from your Mac or PC
2. On a Mac, go to the ~/Music/iTunes/Mobile Applications folder of your Home directory, locate the .ipa file for the app you just deleted from your iPhone or iPod Touch and drag it to the Trash. On a PC, go to the C:\Documents and Settings\username\My Documents\My Music\iTunes/Mobile Applications folder and drag the .ipa file for the app to the Recycle Bin.
Empty the Trash or Recycle Bin
3. Now empty the Trash or Recycle Bin to delete the .ipa file. Note that if you ever need to get the deleted file back, it can always be downloaded again from the App Store for free, even if it's a paid app.
Restore the previous app version
4. Launch iTunes. Switch the view in iTunes to view your apps library. Drag the .ipa file for the older version of the app you are trying to reinstall from your backup and drop it into the iTunes window. iTunes will automatically add the app back to the App Library.
Sync app to your iPhone or iPod Touch
5. Connect your iPhone or iPod Touch to your computer. iTunes should automatically sync the app back to your device. If it doesn't, check your iTunes settings to make sure you have not chosen to sync only "Selected applications." If you have, make sure you've checked off the app in question to enable syncing. Finally, if it still does not sync automatically, you may have to click the Apply or Sync buttons.
At this point, the older version of the app should now be installed on your iPhone or iPod Touch.
If you change your mind, just reinstall the latest version by using the Check for Updates feature in iTunes or by going to the App Store and repurchasing the app, which will be downloaded again for free.