With Apple’s App Store having over 2 million apps available, it can be pretty difficult to find the one specific app that you are looking for. Of these 2 million+ apps, a lot are outdated. Yesterday, Apple sent an email out to developers stating that they will start reviewing old apps on September 7. If they crash on launch they will be removed immediately. Other apps will get a notice from Apple first and you will have 30 days to update.
Apple released an FAQ to explain the changes.