There are a lot of apps out there that pay lip service to security and privacy, but Signal was built from the ground up with the goal of letting people easily communicate without having to worry about being overheard. The Signal app is a complete phone and SMS client replacement (though it works just fine as a standalone app, too) for sending and receiving encrypted calls and messages. A recent update has greatly improved the app's look and feel, proving that security and usability don't have to be at odds.
Runtastic is a smartphone staple, with a simple interface that doesn’t sacrifice advanced features. The no-frills app uses your smartphone’s sensors to track metrics, such as your distance and relative pace, as well as calories burned and your heart rate. A few extra features, such as 3D mapping and a workout diary, only complement the app’s wearable integration. Droid App
The very specific focus of F-Droid is to offer free and open source software (FOSS) Android apps. It’s basic, but apps on the store are categorized, and the list is searchable. You’ll find a big selection of free apps here, all of which promise no tracking, no ads, and no dependencies. It’s worth checking out for free apps, especially if you support the open source movement.
Developers may find Mobogenie to be a great option for selling their apps. There’s an app review process with a snappy 24 hour turnaround, and the revenue split is an attractive 80/20. Mobogenie was originally developed in India and has a large user base there, but also supports multiple languages and could provide inroads into some markets where the Play Store isn’t so popular.
All you need is to hold your Android device close to the source of the song, and after a few seconds, the app will accurately detect the song. Besides, you can also play songs and add them to Spotify playlists, buy songs in Google Play Music with one tap, connect your Facebook account, etc. If you are a musicophile, this Android app is a must-have for you. Droid App