iPhones and iPod touch mobile devices running the Motion Synth App can send musical control signals (MIDI) to MacBooks via WiFi, by either:
Windows laptops can create a WiFi setup using free third party software: http://www.tobias-erichsen.de/software/rtpmidi.html (kindly made available by Tobias Erichsen – please consider giving him a donation for his excellent work!).
iPhones and iPod touch mobile devices running the Motion Synth App can also send musical control signals (MIDI) via Bluetooth LE MIDI.
Any laptop software with MIDI functionality can be used with the Motion Synth App (e.g. GarageBand, Ableton Live, Pro Tools, Max, PD, Reaktor, Massive, etc).
Wireless connections between laptops and iOS devices can get 'drowned-out' by mobile phone signals in live venues. The bigger the crowd the bigger this problem becomes.
In this scenario it is better to use a MIDI cable (eg iRig MIDI) from your iOS device to the MIDI target, or set up a special wifi router that can isolate your signals from the crowd, and is connected to your laptop via ethernet.