I installed from Itunes (the NASS bundled app, v4.0). Iphone still connected to MBP, I started the app. Spinner spinned, paused several times, then iphone rebooted. Second time starting, nearly same behavior but I terminated the app; on restarting, it seems to work. App is very sluggish. Delays in selecting items and loading app.

I have a crash log (from Xcode Organizer) I can upload, if that would help.

Did you try deleting it and then reinstalling it? I have had this happen because my iPhone went to sleep during the download process and it seemed like it didn't get it all or something.... deleted it and reinstalled and it's fine. Worth trying if you haven't.