New setup without local music library

I'm about to purchase a Play 3 and the Bridge.

I keep all my music in Amazon's Cloud.

I do have a local copy which I currently use for my Logitech devices, but to keep things as simple as possible I'd like to just have the Play 3 point to Amazon.

If I take this approach, do I even need to install the software, or can I just download the iphone/ipad software and set everything up?

Thanks