The skill points on the Android/IOS Apps are automatically assigned at the end of the game. You'll need to go into each player skills window and turn off the attribute(s) (Defence/Attack/Physical&Mental) you don't want the App to assign the skill point to. I only use the App when I'm out and about (Windows PC/FB at home) and have left Defence on the GK/Dx/DMx/MC players and Attack on the others. Crude, but it serves my purpose.

What those managers who only use the mobile App do, I will leave for them to explain...