Just the same way I would if I wasn't remote. When working in an office, it's not like people come looking at my screen behind my shoulder anyway (I would hate it).

Basically my activity is visible on the source tracker through the PR is submit and review, the bug tracker, Slack discussions, and we have a daily team meeting where everyone shared what he/she's doing.

We also have a Geekbot on slack so everyone can share what he's done in the day and what he's planning to do the next day.