The air you breathe can directly affect your health. The Laser Egg+ CO2 air quality monitor can measure air quality index, PM2.5, temperature, and humidity. The device has WiFi connectivity and works with HomeKit and IFTTT. It lasts up to 8 hours on battery.
The Kaiterra app lets you monitor air quality from anywhere. It works with iOS/Android devices. The Laser Egg is available for under $200 at this time.