What are some alternatives?
When comparing jstest-gtk and J2K, you can also consider the following products
DS4Windows - DS4 Tool for Windows
InputMapper - Input Mapper is designed to bridge the gap between the devices you use and the games you play.
rejoystick - Rejoystick - A gamepad/joystick translator/keymapper
Xpadder - Xpadder simulates the keyboard and mouse using your gamepad What does Xpadder let you do?
reWASD - First and only gamepad mapper to make Xbox Elite paddles separate buttons.
Pinnacle Game Profiler - Pinnacle Game Profiler enables the use of virtually any game controller (gamepad, joystick, etc.) with any PC game. It's preconfigured for most game titles and controllers. Just download and play.