As the United States continues to flail away at the novel-coronavirus pandemic, my part of it has done one thing right. Wednesday morning, Virginia’s Department of Health launched COVIDWISE–the first digital contact-tracing app shipped in the U.S. on the privacy-optimized Exposure Notifications framework that Apple and Google co-developed this spring.

What that means is that COVIDWISE, available for iPhones running 13.5 or newer and most Android phones running Android 6.0 or newer, requires none of your data–not your name, not your number, not your e-mail, not even your phone’s electronic identifiers–to have it warn that you spent a sustained period of time close to somebody who has tested positive for COVID-19.

COVIDWISE and other apps built on the Apple/Google system instead send out randomized Bluetooth beacons every few minutes, store those sent by nearby phones running these apps, and flag those that indicate sufficiently extended proximity to allow for COVID-19 transmission as doctors understand it. That’s the important but often misunderstood point: All of the actual contact matching is done on individual phones by these apps–not by Apple, Google or any health authorities.

If a user of COVIDWISE tests positive and alerts this system by entering the code given them by a doctor or test lab into this app, that will trigger their copy of the app to upload its record of the last 14 days of those flagged close contacts–again, anonymized beyond even Apple or Google’s knowledge–to a VDH-run server. The health authority’s server will then send a get-tested alert to phones that had originally broadcast the beacons behind those detected contacts–once the apps on those devices do their daily check-ins online for any such warnings.

The U.S. is late to this game–Latvia shipped the first such app based on Apple and Google’s framework, Apturi Covid, in late May. In that time, the single biggest complaint about the Apple/Google project from healthcare professionals has been that it’s too private and doesn’t provide the names or locations that would ease traditional contact-tracing efforts.

I’m not writing this just off reading Apple and Google’s documentation; I’ve spent a lot of time over the last two months talking to outside experts for a long report on digital-contact-tracing apps. Please trust me on this; you should install COVIDWISE.

Plus, there’s nothing to it. The pictures above show almost the entire process on my Android phone: download, open, tap through a few dialogs, that’s it. At no point did I have to enter any data, and the Settings app confirms that COVIDWISE has requested zero permissions for my data. It uses the Bluetooth radio and the network connection; that’s it, as I’ve confirmed on two other Android phones.

If I’m curious about how this app’s working, I can pop into Android’s Settings app (search “COVID” or “exposure”) to see when my phone last performed an exposure check. But I don’t expect to get any other sign of this app’s presence on my phone–unless it warns me that I stood too close to somebody who tested positive, in which case I may not enjoy that notification but will certainly need it.

Updated 8/6/2020 with further details about the app’s setup and operation.