Any App purchased from the App Store can be disabled, by Apple, if it contravenes Apple's strict Developer rules - or if it presents a significant security risk. Whilst possible, this is perhaps an unlikely scenario.
What is more likely is that over time, the App you describe is no longer supported by the App Developer - and, following updates to iOS on your device, is either:
- no longer compatible with your device
- has been removed from the App Store by Developer - or by Apple if the App was abandoned or no longer meets current App rules.
Developers that distribute their products via the Apple App Store are required to “maintain” their code - or they risk having it deleted from the Store.
If the App has been removed from your iPad, and is not not available for download from the App Store servers, then it is lost.
I note the signature in your question suggests that you have an iPad2 with iOS9.x installed. Both of these are very old - and I suggest it is extremely likely that the App in question no longer supported - and has long since disappeared from the App Store.