RocketAPK

See related links to what you are looking for.

APKMirror

Android Market and APK Downloads

Extends the functionality of your web browser

The Amazon Appstore is a place to purchase and download apps for your Android device.

Promote your apps for free and get more installs.

Aptoide is a third party replacement for the traditional Google Play Store.

Download apks from Google Play Store

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.

The project’s aim is to promote free and open source software on the Android platform.

An alternative client app to browse the F-Droid repository

A application for installing apps and updates.

Discover and play paid apps and games for free.

Google Play desktop client

Retro computing interface to Google Play Store

Yalp Store lets you download apps from Google Play Store as apk files.

Zestia is a mobile app designed to assist you in organizing your hectic schedule, social life, and professional persona.