It looks like aftertouch is coming to iOS software synths running on iPhones, via Apple’s recently introduced 3D Touch.
‘3D Touch’ is Apple’s name for the updated screens on its latest iPhones that let the screen sense how much pressure you apply to the display. The ability to sense pressure introduces new options for creating musical controllers and software instruments for iPhones. Previously, aftertouch has been dependent on having an aftertouch-capable hardware MIDI controller.
In the video, via bismark, 3D Touch is assigned to MIDI aftertouch, controlling Bismark’s bs-16i app.
The enhanced sensing capability is currently only available on the iPhone 6s & 6s Plus.