But in my experience that's not too common apps usually work just fine. Most of them will work, but sometimes even once you have the app installed on your it still won't run correctly. This method should at least allow you to have most apps on your outdated device. You'll get a message that says 'The current version requires iOS 6.1 or later, but you can download the last compatible version,' just hit Download. If the iTunes on the computer and your iPad are both signed into the same Apple ID, and the iPad is connected to the internet, then go on your iPad/iPhone to App Store -> Purchased -> tap on an individual app you want to install. Then go to the iTunes store and download all the apps you want to be on your iPad/iPhone. Go onto your computer (it doesn't matter if it's a PC or a Mac) and open the iTunes app. On your old iPhone/iPad, go to Settings -> Store -> set Apps to Off. If you cant restore from an iCloud or iTunes backup because you need to.

Here's the easiest way to download apps onto an old iPhone/iPad that doesn't support downloading apps through the App Store (if you're getting an error that you need a greater software version to download): If restoring from an iTunes or iCloud backup requires a newer version of iOS. The only workaround for now is to install a precedent version of iTunes (see this answer) and follow the rest of this answer. Now that iTunes can not manage Apps, you’re not able to side load them over USB. ITunes 12.7 or later makes this answer into a no - you can’t do it.

Requires a newer version of itunes