You are right; the timeline we were up against was extremely tight because of external deadlines. Crunching to this degree runs an extremely high risk of burn out and is not normal, and I don't believe it is something that should be done unless you are in a do or die situation. I do think it was a management failure that we didn't plan / project manage better, but we're still relatively new to mobile app development.

If we'd had perfect knowledge of what we were going to build in the beginning, we could have cut a lot of time off customer development / exploratory phase of the product development, but I've never realistically heard of that before for a new product.