The apps you install expire after a week. You need to reconnect your device to a computer at least once every seven days and reinstall the custom app. Also, you're limited to three apps at a time.

It's not actually usable for anything. It's also a completely arbitrary and needlessly-punitive restriction—if I've opted in to installing custom software, why limit me to three apps at a time, and why make them only last a week? What security benefit does that provide?