There are two collection modes when recording with the IMeasureU app: streaming and on board. 

Streaming is ideal when instant information is required and the sensor is staying within a close proximity of the device it is streaming to. On board recording is ideal when a higher sampling rate is required and/or the sensor will not be within the proximity of the IOS device for part of the recording. 

The details of the two modes can be seen in the table below:

Collection Mode:
Data Storage:
Streamed directly to device via Bluetooth
Stored on the IMU internal memory
Accessing Data:
Email from app OR upload to iTunes
Download via the Lightning Desktop App
# of Sensors:
4 sensors streaming across a single trial
8 sensors across 2 active trials
Frame Rates:
3-Axis at 500Hz9-Axis at 100Hz
3-Axis at 1000Hz9-Axis at 500Hz
Time vectors of all sensors sync-ed
Time sync information relayed to app when in range of IOS device