Holderness Media says that Stereo Designer is an easy to use multi-purpose stereo shaping tool for Audiobus and Inter-app Audio. They tell us that you can create unique wide stereo images, "stereoize" a mono sound source, apply mid/side processing, independent high and low pass filters per channel, and more. Here's the details in their own owrds:
Process synths, drum machines and hundreds of other apps by connecting through Audiobus. Use Stereo Designer as an effect inside Garageband, Auria, Cubasis, and AudioShare using Audiobus or Inter-app audio.
Stereo Designer features two distinct modes: PERFORM and TWEAK.
In addition to Audiobus and Inter-app Audio support, Stereo Designer can also process external instruments such as guitar, voice and synths by connecting a microphone or professional audio interface such as the Apogee Jam, ONE, or any iOS compatible USB audio interface.
Pricing and Availability:
$2.99 on the app store.
A modern classic that you will find in almost all high end studios