You can take all 3 discounts at once or one at a time. Separately discounts:
1) Depth Hunter 2: Deep Dive - 3 steam cards any games or 85 gems
2) Rapture Session & Pro - 1 steam card any game or 50 gems
3) Big Brain Wolf - 2 steam card any games or 65 gems
I have 3 discount for 2 steam games and 1 music app:
1) Depth Hunter 2: Deep Dive (75%) - http://store.steampowered.com/app/248530/Depth_Hunter_2_Deep_Dive/
2) Rapture Session & Pro (50%) - http://store.steampowered.com/app/352290/Rapture_Session__Pro/
3) Big Brain Wolf (66%) - http://store.steampowered.com/app/35600/Big_Brain_Wolf/
5 steam cards any games or 150 steam gems.
You can take all 3 discounts at once or one at a time. Separately discounts:
1) Depth Hunter 2: Deep Dive - 3 steam cards any games or 85 gems
2) Rapture Session & Pro - 1 steam card any game or 50 gems
3) Big Brain Wolf - 2 steam card any games or 65 gems