Ive been playing with my new inReach satellite communicator and I love it.
Sadly I think the app needs some work.
First, if I turn off my iPhone while a message is sending, the message will be sent again when the app is opened again. This can be a very expensive issue in turns of either duplicate messages being sent, or battery life.
The second issue is with the social networking feature. Unlike MapShare, with shows both in your message thread AND your address book, Twitter and Facebook only appear in the message threads. That means you cant send a new message to both Twitter and Facebook. Also, sending a message to my spouse, a friend, MapShare, and Twitter would require sending two satellite messages instead of one.
Otherwise the app is fairly clean and simple. The Maps could really use a POI search feature but otherwise the interface is clean and simple.
b.forbort about Earthmate