Dead Trigger is for free now. I had seen this on Google Play. The same game my friend has purchased for $1 on iPhone. When I searched on Google I found that because of high piracy ratio on Google Play, the developer has thought to give this for free. Now I am not able to understand why they did this.
The game was chargeable before and now it is for free. Surely those who had purchased the game are not happy at all. But one thing came into notice because of this issue, that Google Play has lots of pirated products. That means free products mostly which are almost paid when you go for them.