> Obviously no one is going to submit an app that doesn't accomplish the primary task.
I would have guessed the same thing before my company started doing homework interviews. But in fact, the ones that don't get to the finish line are sometimes the most interesting ones to review, and they aren't an automatic no-hire. (And we say so explicitly, if a bit more diplomatically, in our instructions.) If someone hands us clean, well-thought-out code and it's clear that they honored our time limit and just didn't quite get there before the clock ran out, we'll still talk to them.
I would have guessed the same thing before my company started doing homework interviews. But in fact, the ones that don't get to the finish line are sometimes the most interesting ones to review, and they aren't an automatic no-hire. (And we say so explicitly, if a bit more diplomatically, in our instructions.) If someone hands us clean, well-thought-out code and it's clear that they honored our time limit and just didn't quite get there before the clock ran out, we'll still talk to them.