Purchase for users on multiple devices

I only recently found leaextendedinput and plan on using it with my Iphone in addition to running it on a couple of Windows devices, one of which operates alternatively with both Windows and a Linux Debian. 

Will I need to purchase multiple licenses to use the program on all my devices or will a single purchase provide for multiple devices? Figured I should find out before I put it on the least useful device I could possibly use it with.

Thanks everyone, and if anyone else plays Elite Dangerous and uses this with playing- I would appreciate finding out the macros and setup being used?

Have a good one everyone- Reaper