Recently I met with two nice slim men who have just launched a weight-loss app that provides daily menus and recipes, and offers some substitutions in case the user does not like a particular food.
The two are programmers who have little understanding of their target market and have not read much of the relevant literature.
I must confess that I was appalled at their ignorance of nutrition, psychology, game dynamics and even women's magazines. Yes, they mean well, and they feel their users' pain.