I’m not completely sure on the compatibility with iOS 5.1.1 but there are a few you could try;
1- GeoShred Pro.
2- Aphelian.
3- Gestrument Pro.
4- Spacecraft.
5- TC-11.
6- NOISE.
7- Borderlands Granular.
8- Refraktions.
9- Poly 2.
10- Touchscaper, Moodscaper and the ambient beast SynthScaper.
If you have any issues with compatibility then I suggest you use Checkra1n and do a basic J-A-I-L-B-R-E-A-K!!!
Then in cydia sources add the repo;
https://repo.appweleux.com/
This will give you some excellent features for your iOS 5.1.1, infact here’s the tweaks you can use and remember not to add or install anything else from untrusted repos unless U know Cydia and how it works;
1- AppSync Unified. (install unsigned/fake-signed apps iOS 5 to iOS 14.2)
2- AppStore++ Upgrade/Downgrade apps in appstore.
Their are many more tweaks such as the ability to get InApp Purchases for free etc.
You can now force the Compatibility of any app, even New ones but it’s not a guarantee with all of them.
Good luck and I hope you have fun with these apps, enjoy.
Azid101