using controller in other games
 

is it possible to use realflight's controller in computer apps and games

Yes, but why would you want to?

The Interlink appears to be a standard Joystick controller to Windows. You can calibrate it from the Control Panel and use it for other games, etc.

Given that it is the copy protection mechanism for Realflight, it's an "expensive" joystick.

You can purchase a USB RC style transmitter/joystick for under $20.00 USD that will behave the same way and use that instead for your other games and RC programs.