Breathalyzer for Plaque?

Over the years, dentistry used a few at-home tools for measuring brushing compliance. Do you remember those pink tablets that showed plaque on the teeth? 

 
Naturally, everything has now gone digital. The maker of a DIY breathalyzer tool has developed a new device for detecting poor oral hygiene. Essentially, the device measures bad breath (using your cell phone) and from that gauges your brushing/flossing adequacy. The idea makes sense: the higher the amount of bad bacteria in your mouth, the worse your breath stinks. Bad bacteria cause tooth decay and gum disease, and we reduce their numbers by brushing twice per day and flossing (once per day). 

So is this new gadget necessary to maintain good oral health? Of course not. But for those technology lovers, it's great way to focus on optimal oral hygiene practices.