The app is quick and simple and will almost instantly give you an outline to work with. That said, it would be nice to have some checks in place to weed-out some of the more obvious contradictions.
For example, the first character I generated was born into an upper class family with much wealth, but lives in the servant's quarters. Temporary housing maybe...? The dad is a physician/thief/master trapmaker. The main character is an only child, but his sibling (the one that doesn't exist) ran away for a few months. They live in an arid marsh. One of his personality traits is trusting 6/suspicious 4, then on the next line it is trusting 4/suspicious 6.
The program is useful and with some common sense these problems are quickly eliminated, but some of the glaring issues (such as the sibling thing) I would expect to be caught and rerolled. Three stars for a good product that is rough around the edges; it would benefit greatly from some logic in the code to catch some of these issues.