Songstack - Swipe to discover new music for Spotify
Hype Machine - Hype Machine lets music fans discover artists. Its technology scrapes audio files from diverse music blogs and posts them to the website. Users can peruse the site or sign up for Hype Machine's newsletter for updates.
BandNext - Discover bands that sound similar to artists you already love with BandNext. A single click saves your results to a Youtube playlist.
Noted - Social music discovery
22tracks - DJ curated Spotify playlists on iOS
Liyo - Stream your favorite music live with friends 🎶