And right there shows the folly of human powered anything. The recharge times for even basic items is way beyond realistic for most anyone to deal with.
Olympic cyclist gets wiped out making 1 slice of lightly toasted bread with a bicycle generator. ~one minute at ~ 700 watts output or ~ 12 watts of power. Just enough to charge a cell phone.
Guessing a fidget spinner generator would take well over 24 hours to charge phone provided that it could even break the minimal power requirement levels to even start and maintain the actual charging process which I doubt being most phones need at least a stable 5 volt .5 - 1 amp source to work which is way beyond what finger power can produce steady.