As the developer of the Android IGCDroid phone tracking app I'm biased.

The phone app is actually sending an entire IGC file piece by piece in near real time. So, positions are recorded up to once a second, buffered on the phone and sent in blocks once every minute or so. The exact sending interval depends upon cell coverage. The app wants to send data as quickly as it can but also needs to consider your phone's battery life.

The final results you get from a phone tracker depend upon lots of thing, the quality of your phone, mounting in your glider, cell tower coverage. I have seen flights that update faster then spot. I have seen flights that update much, much slower than spot. Its this unreliability that makes Lane say this is for entertainment. I think that is slightly harsh, but I do agree that I wouldn't trust my life to it.

Personally I fly with a PLB and my phone. I don't use Spot or InReach. Everyone needs to make their own personal safety cost tradeoff.

One big down side I personally see with IGCDroid is that the data is addictive... I REALLY, REALLY, hate not seeing the data updating for a long time.. With Spot I don't hate not seeing the data as much because I don't like the data as much.

Alan