Im using IPad 4 IOS 10.3.3 is its latest software and this new app says it won't let me download unless I have IOS 10.3.3 which I DO! I've also restarted the IPad
iPad (4th gen) Wi-Fi + Cellular, iOS 10.3.3, Running Great
From the information Specified by you iPad (4th gen) Wi-Fi + Cellular, iOS 10.3.3
The iOS is the latest you can get for that device.
I suggest you try to Delete the App and Reinstall it.
Just make sure you Backup your Device.
How to back up your iPhone, iPad, and iPod touch - Apple Support
I deleted and reinstalled Still nothing Infinite Flight Developers are looking into the issue On app store
So to confirm this problem is only pertaining to this particular App ? or to all the Apps you are trying to Update?
IOS 10.3.3 won't update an app
