Of course, while there are obvious advantages to having a phone with a giant mirror on it -- being able to check for parsley in your teeth, blinding annoying siblings by angling the phone at the sun -- the downside is that you will need to spend a lot of time doing the old spit-and-polish. The surface quickly becomes tarnished with fingerprints, facial muck and unidentifiable grime, so keep a wiping cloth handy.