Last FM is the most underrated app. Only the coolest people I know use it and it has this low key vibe to it all. Just checking my listening records, reason about artists, seeing what my friends are listening to, and finding new artists is great. I like that it's not always begging for my attention or overloading me with notifications. Whenever I go to Scan my scrobbles I'm always happy to see how my records look in the last week and last months.