Every couple of weeks reports of influenza
epidemics and gastrointestinal viruses appear on the news. In most
cases, it’s a matter of insufficient hygiene and the spread of germs.
The problem is that you can’t see these microscopic threats with the
naked eye. But your phone will shine some light on the truth. Literally!
It's really alarming what's revealed. This little trick will now be part of my standard repertoire. Better safe than sorry! (Source)