Paku - iOS App for PurpleAir

I wanted to share my app, Paku, with the community, as well as open a thread for feedback and suggestions. I’m the developer of Paku, an iOS app for PurpleAir that also has Home Screen and Lock Screen widgets. I have a small website up at, or check it out on the App Store [here](


Well done! What an awesome app! Would it be possible to make one for Android Devices as well? Thanks!

I just installed my monitor and I can see it on the purpleair map/website, but it is not showing up on Paku on my phone. Does Paku update on a schedule as opposed to real time?

Yes, the app only updates its list of sensors once a week automatically. You can open the settings and tap “refresh sensors” to do so manually. Let me know if that doesn’t work and I’ll look into it for you.


This is great. Thank you !

1 Like

Hi, thanks. However, the values read in Paku are almost 30 points lower than those on the For instances, a local sensor is showing a now value of 61at, whereas Paku shows 36. And when selecting the “Open in Purpleair” option, it opens, but with this same ~30 offset on all the values for the sensors. Seems a bit misleading maybe (air indicated as better than it is).

Also, a bit less frequency on “rate the app” request might be good too :wink:


Hi Robert,

I suspect this is due to the default EPA conversion applied in Paku, which applies a correction factor based on a study by the EPA on PurpleAir sensors that is usually more accurate. You can disable this in the settings.

Regarding ratings: are you on macOS or iOS? It should only prompt once in a while, though I suspect there’s a bug in macOS.

1 Like

Thanks for the quick response. You’re right - once disabling the EPA conversions, values match the readings. Interesting that the EPA suggests cleaner air, and wonder about the logic behind such a large difference between them and purple air.

I am using iOS, but was in and out of menus, while becoming familiar with the app (and trying to figure out the ~30 offset). If it continues, I’ll reply back here.


For anyone watching this thread, I’ve begun the work to add push notification support. If you’re interested, follow along here: Would you like to help me test (iOS) push notifications PurpleAir sensors?

I monitor pretty closely, so wouldn’t need a push notification (and get enough notifications from other things!). But I could see how this could be useful for the more lay user.

If you’re compiling a list of potential improvements, being able to see the values of both the A and B sensor would be helpful. I know one of my sensors, A, tends to skew high, so I rely more heavily on the B value (the dual sensor was just purchased as replacement!). I only see one value in your listing by time (i.e. Now, 10m, etc), so assume that is the averaging of both.

Also, when selecting the sensor, which brings up that value versus time window, I’ve somehow got the sense that it’s not truly updating at the 1 minute rate I had been use to (with the now defunct Sensor data download tool), or not updating at all. If I exit that window, and re-click the sensor on the map, it brings up a new (assumed later) value.


Nice app. I really like it. Well done.
Any new features in the road map?

A shame that it requires a newer version of iOS than my phone supports.

Hey Travis, you should be able to download an older version from the App Store still. It won’t have all the latest features, but still has a lot of functionality. If you try to download the app it should prompt you to download the last 4.x version.

Sadly not the case, requires iOS 17.0, and I use an iPhone 6s Plus, so I can’t even get that.