Numu Tracker got a website version this week. It’s meant to have essentially all the same features as the iPhone app, but in web-form. It’s obviously in a different visual style than the iPhone app, which I know might perturb people in one direction or another. Either way, you can sign up, log in, follow artists, and mark releases as listened to. It currently has an extra feature the app doesn’t: user stats, showing you how much of your release library you’ve listened to.
There’s still some polish and refinements to be made, like I recognize that the ‘follow / unfollow’ squared-circle on artists is confusing and should probably skedaddle or get replaced with something else.
Eventually I will build in import functionality for Last.FM and Spotify. I’m also planning some “lite social” features, like allowing you to set a username so your username appears in an “activity list” that shows up on release and artist pages, like “Amiantos listened to this 2 days ago.” (Without a username it’ll display “Somebody listened to this 2 days ago.” instead.)