Sorry for the confusion however I can explain what is going on. The app was updated recently to support 2.1.7 and the check for GPIO stations got modified to support all 2.1.7 devices instead of just the Pi on 2.1.6+. The check for this option is now checking for 2.1.7 so the latest app is incorrectly graying out the option. The firmware update should be released by tomorrow, as I understand. Once out, you can update and the app will correctly show this option.