Loopster 4+

Loopster plays back audio files and lets you change the playback speed independently from pitch and vice versa while keeping the best possible audio quality of the stretched and / or transposed output.

Many apps around have these features and maybe many more but the unique concept of Loopster is the way you can operate it.

While you practice your songs or transcribe them, you control Loopster easily with single key touches on your keyboard. No mouse, scrolling sliders, you do everything with the touch of one finger.
The author himself is musician and created this app for his own and all practicing musician's needs. 
Its great looking and easy to understand interface is the difference and this is what gives you more practicing fun.

You will get the best out of Loopster if you operate it as intended, by using the keyboard and not the mouse.
It is designed for practicing by holding an instrument whilst temporarily having on free hand to control Loopster.

Transpose songs in up to 12 halftone steps up or down without affecting the playback speed.

Tune Songs in steps of one hundreth of a halftone to match your instruments pitch.

Change playback speed without affecting the pitch.
Of course, you can also change both tempo and pitch simutaneously.

Manage you songs in playlists.
Store and easily recall up to 10 loops and locators per song using the number buttons of your keyboard.

Intuitively use the keyboard keys indicated on buttons and get easy and fast access to all functions.

Modify any value (e.g. speed, pitch, loop in and loop out position) with the arrow keys of your keyboard. This will make your practicing, rehearsing or transcribing experience much more comfortable.

Manage songs of different bands or projects in playlists.

Your Loops, Locators, Songs and Playlists are stored automatically when you create them.