Scloudy is a simple to use music app that you can use to discover new songs from SoundClouds incredibly massive music database. This is done by simply entering in some keywords (such as "Pop,"remix","Kendrick Lamar",etc.), entering optional track duration values, and optional track BPM values to match the kind of music you are in the mood for. Whether you are at home and want some laid back classical music or running outside and want some high-BPM tracks to match your intensity, you can find it all using Scloudy.
There is also an apple watch app that comes with this app which can be used to control the app and also get track info.
Give it a try!!