PaulXStretch

This application and AUv3 plugin is based on the PaulStretch algorithm, (Paul’s Extreme Time Stretch, originally developed by Nasca Octavian Paul), and specifically the PaulXStretch version from Xenakios. The UI has been updated and adapted for various platforms and screen sizes.
The plugin/application is most suitable for radical transformation of sounds. It is *not* designed for subtle time or pitch corrections! Ambient music and sound design are probably the most suitable use cases. It can turn any short audio into an hours long ambient soundscape without batting an eye!
You can get audio into it either by using the "Capture" feature, or by loading an existing audio file. Once you have something in there, then you can start tweaking all the parameters, choose the portion of the audio to use and loop over, etc. Be sure to press the play button inside to enable the processing. To get your audio out, you can do an offline render of the output to a file (where all parameters are fixed), or you can do a live recording of your session to capture the output as you hear it. Either way, you can then share or access the saved audio from the Files app or by sharing it.
The AUv3 plugin version has the same capabilities, except you can feed it the live input of your choice (to capture internally for stretching).
This software is free, please enjoy it!