Were there any particular titles that were especially challenging to write trainers for? (ie, "oh gawd, not this one again . . ."
About your second question: Early access, games based on Unity Engine. There are not difficult, they're just 90% of the time purely annoying.
But there is nothing, really nothing more annoying as game where the developers changed the code on every f... patch and you need to start from scratch.
* Updated game trainers and cheats daily
* Get notified when new cheats are added
* Request which games get new trainers
* Priority support with any problem