Embed player in app

[sroebert]

For an iOS/Android app I need we want to integrate a Spotify player inside our own app. We would like to either play a single track or a playlist, which will be fixed for the user.

We have looked into embedding using a web view, but this has quite some drawbacks. The main issue here is that the user always has to login at least once, even if they are already logged into the Spotify app, or through the phone's webbrowser. 

Can anyone suggest the right approach for this (if even possible), maybe using the SDK instead?

Also for this integration, would we need permission from Spotify?