Instructions to complete app chanlenges

So I have visited AdgateRewards android offers, and there are two apps SearchMyPhone and PrankPulse, they are both published by CoolBoots Media at the google play store, challenge is "Watch a video" , well to try all the option I have watched like 10 videos or more on each, but the offer is still no complete.
Before I join future offers is there a place that I can check tutorials to get an idea of how these work ?