IOS and MIDI developer required for cutting edge music app

IOS and MIDI developer(s) required to complete an existing music application that communicates over BLE to a custom hardware device. The application will need to transfer data between the app and hardware and visa versa. Overall system latency is critical. Plus we will need to implement a new simplified user interface. Successful applicant(s) will need to perform a full audit of existing code. Imbedded ARM experience would be a huge bonus.