Are there apps for operating system 12.5;

While there are many Apps available that remain compatible with the iPad Air1, mini2 and mini3, they are becoming increasing fewer in number.

Apple does not provide a listing of Apps available by iOS version - and neither does the App Store provide a filter by iOS/iPadOS version. The best that you can achieve is to search for Apps in the App Store for which you have interest - and then check compatibility for your iPad for the individual App.

Third party app support, typically, continues for 2-3 years AFTER Apple ends full support of a subset of their devices.

The last major update to iOS 12 was in 2019, with iOS 12.3.

Apple has stopped issuing any major iOS 12 updates for these very old iPad models and have been ONLY issuing security, “point” updates for the past few years.

So, year three is coming to an end and third party app support has been on a steady, downward/decline trend for all iOS 12 supported devices.

Many popular third party apps are no longer available to 9 to 10-year old iPad models that are, permanently, stuck at some version of iOS 12.

Look for many more third party apps dropping support for all iOS 12 supported devices as the 2022 year progresses to its end and into the beginning of 2023.

The immediately above statement is what you really need to worry about.

Sorry, but this is the reality for all over 8 to 9-year old iOS 12 ONLY supported devices.

Only whatever apps have already been downloaded if they are still supported.