The Bimmercode app really is pretty simple. It can't do everything that some of the other methods can, but there is almost no learning curve, and the app and required OBD II adapter are both available for less than $50 total. The app's author is constantly adding things to the 'simple' mode, and the expert mode is still there if you feel comfortable working in that (plus, it does a backup, so you can go back if you don't get the results you want). Keep in mind, 'coding' a BMW is done by flipping 'switches' already in the software...the basic code is not changed. Then, if the car goes in for service, you can restore your preferences without having to pay someone all over again. Almost any software update done by the dealership will reset everything to factory defaults, so having the ability to restore your preferences is a good idea.
2011 535i x-drive GT, 2014 i3 BEV