First off, I wanna say great job, this app is great, I'm definitely buying pro version in the near future.

However, it is lacking a quite important feature for oldschool shooters enthusiasts - invert mouse.

The origin of inverted Y axis are flight simulators, which were the first truly mainstream first person perspective games. In them pulling controller towards yourself makes aircraft ascend (like, well, in an actual aircraft). This created a habit in gamers which was recognized by developers of early FPPs like Duke3D and Quake, and the option sticked to this day. A large portion of older FPS gamers are unable to play without it, it's like writing with left hand for them.

It would be great if this option could be added as a tickbox in controls menu, or at least be configurable in .ini by setting mouse speed value at negative like "-5".

Good luck on further development of this project!