Sometimes updating an app doesn't exactly mean it's going to be better. Sometimes you actually realize that the new update is buggy and not worth having, so you want to go back to the previous version.
At first this might seem hard to do, but it's not! You just have to make sure you did not sync your iDevice to iTunes after you upgraded the app you want to downgrade. If you did, then this won't work anymore for you, unfortunately.
Downgrading Apps on iTunes
- Step 1: Delete the app you want to downgrade from your iDevice.
- Step 2: Connect your iDevice to iTunes using the USB cable. DO NOT LET IT SYNC!
- Step 3: Click on your iDevice's name and head to the apps list. Click on Install next to the app you want to downgrade.
- Step 4: Click on Apply on the bottom-right corner of iTunes.
That's it! The app should now be downgraded.
Remember that if you upgrade an app and sync your iDevice to iTunes after you've done so, you won't be able to downgrade it anymore. This happens because before you sync your iDevice with iTunes, it will only have the older version of your apps saved. This way you can install those versions until you sync the new ones.