It couldn't be easier to use 3839. The interface is divided into to various different tabs, where you can easily access tons of apps and games of all kinds. You can check out lists of popular apps, specialized articles, and so much more.
To download any game, you don't have to create an account. All you have to do is tap the download button for the game you want, wait a few seconds, and install the APK. Immediately, you can start playing any game you've downloaded.
3839 is an interesting alternative for finding games on Android, especially if you're interested in Asian titles. One of the main factors to keep in mind is that many of these games reach China or Japan first, before they make their way west.