PS4 Trainer Utility, Bloodborne Trainer, Dark Souls 2 Trainer, Dark Souls 3 Trainer and now TylerMods made available a PS4 Trainer Tool Payload for use with Project Mira CFW + HEN enabled on PlayStation 4 jailbroken consoles.
Download: PS4 Trainer by TylerMods.zip (39 MB)
It's currently at v126.96.36.199 and available on his RivalGamer.com forum thread with support also available on the PS4 Source Discord, and to quote from @TylerMods there:
Here is a trainer for PS4 that I have been working on and it is not 100% just like PS4 modding isn't. I will NOT be adding GTA or COD to this tool. I hope everyone likes it and finds it helpful.
YOU MUST ENABLE MIRA+HEN FIRST TO INJECT THE PAYLOAD
I cannot stop you, but I do ask out of respect if you guys would not decompile my tool. Thank you.
Make sure you have the correct CUSA and version of a game.
Resident Evil 4 & Resident Evil 5, God Of War Game Trainer/Tool For Jailbreaks by @Andrew Marques
Finally, there was also an Orbis Loader AND GenGP4 Keystone Patched by LMAN recently released worth a peek for those tinkering with PS4 Keystones.