This app was mentioned in 1 comment, with an average of 2.00 upvotes
If you've got any intelligent lighting fixtures, especially those of the older/cheaper variety, a dip-switch calculator is a must. I use https://play.google.com/store/apps/details?id=com.adl.dmxcalc - handy as it can increment in whatever interval you want; as well as change which way is 'on'.
Additionally, a gel colour picker app and RGB colour picker, if your desk doesn't have one.