[Windows, Mac] $0: Riffstation (Was $34.99 for Guitar Players & Musicians) @ App Store

Seems like good and useful app on MAC & Windows.Very good ratings.

Link (Thanks to Rygl) : https://pro.riffstation.com/download/

Riffstation is the ultimate app for guitar players and musicians to practice and learn the songs they love!

Load any song from your existing music collection (mp3, mp4, aac, flac, ogg, wav, aiff) and it automatically calculates and shows you how and when to play each guitar chord synced with the original music. In auto mode, it can detect maj, min and 7th chords with approximately 85% accuracy. Sus chords and maj/min 7th chords can be added manually.

See the guitar chord diagrams and hear the original music in perfect synchronization in any key, at any speed.

Slow down the music without affecting the pitch or change the pitch without affecting tempo. Transpose the song into any key you like.

Isolate the guitar track so you can hear it in greater detail. Or you can get rid of the guitar player in the mix and join in yourself.

Loop difficult sections with the beat synced loop tool. Now you can create perfectly timed loops to practice with.

Add an automatic metronome to the music to help with your timing.

Create custom jam tracks by rearranging the riffs in your favorite songs.

It does all this with the digital music collection you already own. No new content is required.

FEATURE HIGHLIGHTS:

• Automatic Chord Detection and Synchronization
• Real-time Chord Diagrams
• Supports mp3, mp4, aac, flac, ogg, wav, aiff.
• Audio Slow Down Tool (half speed up to double speed)
• Pitch Shift and Transposition Tool (- 1 octave to + 1 octave)
• Loop Tool with Automatic Beat Synchronization
• Guitar Isolate Tool (mute or solo the guitar track)
• Riff Builder Tool (create custom jam tracks)
• Save Processed Audio
• Save Session Settings

• Sleep Sounds: relaxing sounds EXPIRED

Sounds was recorded in most beautiful places around world.

All sounds recorded with high quality stereo condenser microphones and preamps. (besides generated sounds: white pink brown noises and binaural beats)

Additional features:
Auto off timer
Reliable alarm clock

Sounds:
white noise
pink noise
unicorn music box
teddy bear music box
ballerina music box
cat purring
morning forest
creek in forest
forest
tropical jungle with tree frogs
loro park
bonfire
heavy rain
heavy thunder
distant thunder
rain under umbrella
rain near window
light rain on street
rain on city street with traffic
sea with seagull
sand beach
baltic sea beach
underwater volcano
night sea
wind in open window
wind at the door
london train station
australian subway
moscow subway
chinese bus
highway
new york silent street
highway bridge
oscillating fan
3D printer
old radio tuning
old english clock
vacuum cleaner at work
wind chimes
gong 40"
gong 38"
binaural beat 1Hz lethargic
binaural beat 2Hz deep sleep
binaural beat 3Hz dreamless
binaural beat 4Hz drowsy
binaural beat 6Hz fantasy
binaural beat 8Hz relaxed
binaural beat 12Hz conscious
binaural beat 16Hz focus
binaural beat 24Hz active
Roscoff port
Amazon rainforest at night
Pazin, Istria (Croatia) at night
Eidar river (Iceland)