This app was mentioned in 3 comments, with an average of 6.33 upvotes
Here's a link to the few version:
https://play.google.com/store/apps/details?id=com.hg.gunsandgloryfree
The free version seems to have quite a few ads so the premium version could well be worth it, especially for £0.10.
ads AND IAP in this?
What's the difference between premium and the free version? https://play.google.com/store/apps/details?id=com.hg.gunsandgloryfree
I think you're looking for Guns'n'Glory by HandyGames.
https://play.google.com/store/apps/details?id=com.hg.gunsandgloryfree&hl=en_US
EDIT: You said iOS.