My greatest, easiest AHK script ever - Instant application switching
Channel: Taran Van Hemert
Date: 2016-11-11

NEWEST CODE WITH 'BACK' BUTTON and VARIABLE APP:
https://github.com/TaranVH/2nd-keyboard/blob/9ee39aaccf9c58df9c4a7c19eb7d12ab5223872c/Almost_All_Windows_Functions.ahk#L570
NOTE: The functions are CALLED from this separate script. You can put them both in the same script, though.
https://github.com/TaranVH/2nd-keyboard/blob/9ee39aaccf9c58df9c4a7c19eb7d12ab5223872c/ALL_MULTIPLE_KEYBOARD_ASSIGNMENTS.ahk#L1253

THE OLD CODE THAT IS FEATURED IN THIS VIDEO: https://github.com/TaranVH/2nd-keyboard/blob/master/Taran's%20Windows%20Mods/CUSTOM%20MOD%20-%20F1F2F3F4%20-%20program%20launcher.ahk