Slowing things down

I just purchased the Mobile App Promo from the the theme forest. It’s a great theme; but it runs so quickly!

I’d like to slow things down but I’m having trouble. I tried using a Time Stretch but the position/shape of the Screen Comps and the phone models fell out of sync.

Maybe my question is really an After Effects question; I’m an After Effects noob. But if I want to keep each segment on the screen for 2-3 times as long; what should I do?