Every app on a phone competes with FB, YouTube, Amazon, and more. And most of these apps are hacked together rush jobs rolling out to distrustful users. Bad combo for engagement and retention. Listen to @meganranney! https://twitter.com/meganranney/status/1277795694301110274

There are real privacy concerns around these apps. Under this administration there are many who will decide that giving the state their data is more risky than staying blank to contact tracing. And sloppy fast development leads to plain old privacy breaches, too.

What we do know about engagement and retention so far is that a) physician prescribing an app and b) payment to users appear to be the only significant contributors to higher retention. See @abhishekpratap here: https://www.nature.com/articles/s41746-020-0224-8

So if you want people to use these things? Get docs to prescribe them, pay people monthly to keep them installed and turned on. And don't give the development contracts to tiny, local startups who will rush the job.

But it's mostly hypothetical as long as runs the show.

I encourage you to look at the maps in the Pratap paper of enrollment and retention in digital health writ large, and contemplate electoral maps while you do so.