We’re very sorry about that. Could you email us any crash logs still on your device? You can check by going into Settings > Privacy > Analytics > Analytics Data when you tap a crash report prefixed with Agenda can you tap the export icon in the top right corner and email it to me at alex@agenda.com?
I also experience this bug. I did find that if Agenda is the first app open, its less frequent to crash. If another app is open first (not only Safari), It will crash the majority of the time.
If the crash does occure, it still keeps both apps running in the background. They have to be physically closed and restarted again in the correct order.