The legendary FPS titles Doom and Doom II are now finally available for iOS and Android handsets. While they are not free, they come for a fair price of US$4.99 each. Doom includes the "Thy Flesh Consumed" expansion and Doom 2 comes with 20 new levels, four-player co-op, and four-player multiplayer.
https://www.notebookcheck.net/Doom-and-Doom-II-now-available-for-iOS-and-Android.428335.0.html
Doom was a lot of fun with modified sound packs. I had a comedy one that had the Pinkies saying "Tickle! Tickle! Tickle!" when they got close to you. The rocket launcher would say "Fire fire fire" in a Beavis voice anytime you shot it. ;D
Wow, that would be something to do - installing sound packs on the mobile versions! I wonder if that's even possible - it should, but you never know with the mobile permissions nightmare.
Adding custom sound packs to Doom II will be the feature that pushes iPhone users to Android in 2019.