More specific software can be found in the MIDI, VST, and DAW sections. Some of the essentials are below.
- Music Speed Changer - song player with adjustable song tempo. Allows slowing down songs for transcription.
- iRealPro - jazz standards, playalongs.
- Spotify - listen to classics.
- Google Play Music - upload own songs.
Audio File Converters
- Free Audio Converter (link)
- r8brain (link), a free tool for resampling and changing the bit rate
- MP3 quality modifier (link)
Music applications for creating music in the Garage Band style.
- alternatives for android (link)
See VST page.