ARPAY - Buy gift cards at ar-pay.com, which allow you to access your favorite internet services: online games, e-wallets and console games, online shopping cards and many more!
Amazon Appstore - The Amazon Appstore is a place to purchase and download apps for your Android device.
G2A - Enjoy the vast offer of Steam, Origin, Uplay, Battle.net, GOG, PSN and XBOX CD-Keys at the most attractive prices on the market. Don’t overpay – buy cheap on G2A.COM!
GetJar - Discover and play paid apps and games for free.
Kinguin - Marketplace to buy/sell game keys for a myriad of platforms including: Battle.
F-Droid - F-Droid is an interesting alternative for Android users who want to try something different and not have to use the Goole Play store all the time.