Synthtopia publishes details of the MIDI Mobilizer FAQ:
Can I use MIDI Mobilizer to control synthesizer applications or play other music apps on my iPhone?
This is technically possible, but would require software updates to each application in order to communicate with MIDI Mobilizer. Additionally, the developer of the application would need to become a Line 6 MIDI Mobilizer developer in order to be given the development tools, and allow Line 6 to publish their MIDI Mobilizer-enabled version (currently, all applications for a hardware accessory must come from the same publisher).
If there’s an application you’d like to see work with MIDI Mobilizer, please have the developer contact MMdeveloper [at] line6.com for more information.
This is the bit that I don’t get. Does this mean that developers will need to hand over their apps to Line6 for them to publish the version that works with the hardware? Will developers do that?