I've lived in Oregon for a decade, meaning I've experienced multiple wildfire seasons. You learn quickly, in these conditions, that staying on top of the air quality is essential: Prolonged exposure to poor air quality can have all kinds of negative affects on your health so you don't want to spend a lot of time outside if the air is bad.Breathable is a newly free app by the Portland-based app development agency Karbon that adds an Air Quality Index (AQI) widget for your iPhone, iPad, or Mac. Install the application, then add the widget to your device to be passively aware of the air quality every time you pick up your phone. (Yes, you could check the AQI in the Apple Weather app, but it doesn't offer an AQI widget.)The application, while free, takes a little bit of work to set up. You'll need to get API keys from at least one service in order to use it. The good news is this process isn't long and there's very clear documentation. You'll need to head to IQAir.com, sign up for an account, choose the free plan, then copy the API key. You can repeat the process at Airnow.gov if you live in the United States and want access to information from the EPA. Then you'll need to specify, in the app's settings, which location you want to get AQI information for. Credit: Justin Pot After setup, though, you just need to add the widgets wherever you like. Breathable offers two widgets, one small and one medium. You can add these widgets to your homescreen on an iPhone or iPad, as a complication on your Apple Watch, or on your Mac desktop. All of those options give you the AQI as a number and in a chart.You can, optionally, customize the look of the widget with the font, gradient, and layout. It's not a lot of customization but you should be able to get it looking the way you like. Credit: Justin Pot You can also decide to show the AQI using an emoji scale instead of a numbersome people find this easier to parse at a glance. The default set uses faces, but you can customize the widget to use whatever emojis you like.The developers of Breathable say they wish it didn't have to exists, and I agree. Climate change is a reality, though, and tools like this help us deal with it a little bit.