I used it some last year. I found the map portion to be the most helpful in regards to knowing how long till next town. I usually have a printed daily map with me but found the app to work due to my usually losing the map somewhere along the way each day. Weather information was also helpful.
The iPhone app is mostly window dressing on a web app, it’s pretty worthless if you don’t have data coverage with your cell provider, which is always a bit of a crapshoot in rural Iowa anyway (I’m looking at you, AT&T).
In a few months, the Android types will be complaining, “Where’s the Android app?”, they’re people too, blah, blah, blah, not realizing they’d be just as well off going to ragbrai.com with whatever browser comes with their phones.
It’s really kind of a shame they don’t have the resources to do a proper app with offline maps, etc. but I’m sure that’s not in TJ’s budget.