The popular mobile game Clash of Clan, leads more players back to phone game. Here I introduce some apps that can earn free gift cards such as amazon, iTunes to buy gems.
1. appnana. sign in and invite your friends, and you can earn credits. when you finish certain tasks and get enough nanas, you can directly buy gems.
2. appsgiftshop. Cannot buy gems directly but easier to get credits than appnana. download the sponsors as it provides, earn credits enough to redeem gift cards.
3. free my apps. The same way as appsgiftshop.
4. appbounty. Accomplish the tasks to get points, or follow its facebook to take part in some bonus activities.
5. feature points. download apps and invite your friends to finish the tasks can earn you credits.

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