Here are the best ways, in my mediocre opinion, to play each comp.
Words: iPad because the screen is so tiny mobile
Lucky Drop: Computer because my computer is luckier than my phone
Deal: iPhone because my iPhone is luckier than my computer
Holey: computer, if you're playing mobile...like what...how?
Match 3: iPad, I tried this today and got my best score
Chainpop: iPad because the balls are bigger
Starfall: iPad, less fear of swiping out the comp
Stacker: computer but I have to make half the screen disappear at the bottom
Codebreaker: iPhone so you can click fastest
Shapes: iPhone, just focus on the colors
Weightlifting: laptop arrow keys - superior
Guitar: nothing, fuck this comp
Flags: anything, study