Which watches work with Pokemon Go?

I am interested in looking into a fitness tracker that would line up with the Pokemon Go app.

I know pretty much nothing about Apple watches.

The main thing is I would like to see about getting a watch that will carry the information to the app.

The articles I've read have said Fit Bit will not. Articles sounded like Polar would but it didn't.

The biggest thing is I'm looking for one that logs the information to transfer to a phone at a later time.

I work in a prison so anything that can communicate on it's own is a no no.