this is related to iOS, not Spotify. On my iPad the problem was that there were age restrictions installed. Go to settings -> General -> restrictions and lift whatever (age) restriction might be blocking spotify.
I've done this and it didn't help. When I click on the download cloud it looks like it is starting then goes to the stop button. Then you click this andgoes back to the cloud. Never actually downloads! Help! I have paid version and would like to use it!
I solved this issue clicking the download button a LOT of times unit after a good while of click after click it downloaded. Even restoring the phone didn't work. Just keep a good amount of time trying.
This was happening to me, and I tried turning off my phone, signing in and out, pressing it twenty times, to no avail. However, I then went into all my apps that were still "waiting" to download, like iMovie and Garage Band, and deleted them. As soon as I did that, Spotify was able to download. I then re-installed those apps I deleted. All worked perfectly. Good luck! 🙂