Transmit causes lock up

Good app for simple needs. But when transmit signal is switched on the app locks up (on an iPhone 6, iOS 8.1).
I use this for kids outreach events to have them build a structure to be shook on a shake table for earthquakes, and see what kind of accelerations their building experiences. Having data transmission would really help speed up some analysis to give the kids results.

Adrian-Crowder about iSeismometer, v1.3