Black Mart (Alpha)
Most convenient provider of paid and free applications. Latest version!
Provides top and popular apps and games. You can find here almost all applications you need. It has a good download speed than Aptoide but the bad side is you don't know which apps have malwares or viruses so better have a protection like Anti-virus for your safety.
In order to install the downloaded APK file, make sure you allow Third-party Applications to be installed in your device or else downloaded APK file will not be installed. To allow just go to Settings, Security and check the Unknown Sources/Non-Market apps.