Pithos is a easy to use native Pandora Radio client that is more lightweight than the pandora.com web client and integrates with the desktop.
It supports most functionality of pandora.com such as rating songs, creating/managing stations, quickmix, etc. On top of that it has features such as last.fm scrobbling, media keys, notifications, proxies, and mpris support.
Terrific when it works, but on two computers it refuses to get past an error message: "Filed to Store Your Pandora Credentials"
Works great for me. Not sure why one reviewer here was having issues with it. I had the non-flatpak version, but starting having an issue with it today. So I decided to try this flatpak version. This has more features than the non-flatpak version in the repository. You can add stations through the app, but I havent tested that feature. You can also sort the stations alphabetically, which makes it easy to find the station you want to hear. You can also select stations for "Quickmix"
Works fantastic. I was torn between this and the GNOME version after seeing the previous comment. No issues at all on 18.3 with current stable 4.13 kernel. Fast, responsive, easy to use, and lightweight.
It's a nice idea, but has severe performance issues on Mint 18.3 with kernel 4.15. Program is responsive, but it can take at least a minute between selecting a song and it starting playing. Similarly, between songs there's a huge wait. So far Pandora in the browser is much better.