What's the best product/app for measuring air quality in a home?

Also links with things like Next and Alexa

A little bulky IMO. They have a new one in pre-launch

As weird as it may seem to see a "home security" product as a recommendation for general air quality, it's actually one of the main reasons I originally bought my Canary. They have awesome little graphs that show you general air pollutant/irritant levels and temperature levels in your home, hour by hour. It's so rad. In addition to having these awesome air data features, Canary kicks ass at it's main function of providing home security. I highly recommend!