I haven't tried this app and should probably keep quiet.
However, I do use a similar app called Torque Pro. It runs on Android devices and I use it on a Nexus 7 tablet. It communicates with the motorcycle via a bluetooth OBD II interface that I leave connected to my 2010 Bonneville T100.
It does work to a point. The app uses the Android's accelerometer, the Android's GPS, and the motorcycle's ECU data to calculate some of the output. It does a good job with 1/8 mile times and finding the rpm where horsepower peaks, but the actual horsepower calculation depends on some data the user enters and I am not convinced it does a good job calculating horsepower for vehicles as light as motorcycles, but it may be that I just have to be more precise in entering my motorcycle and rider weight.
I don't remember where I read it, but there is a forum where iPhone users are talking about using apps like this for Apple devices and motorcycles.
I am pretty sure that many cars log more data that our Triumphs so these apps may do more with cars than our bikes. On the other hand, few motorcycles use the OBD II protocol so we are lucky to have even this and TuneECU.