Formitor updates like any other WordPress plugin — no downloading and re-uploading a zip.
One-click updates
When a new version is released, each site's Plugins screen (and Dashboard → Updates) shows an update notice for Formitor with a one-click Update now button. Click it and the site is current.
Check for updates on demand
Don't want to wait for WordPress's periodic check? Use the Check for updates link — it's on the Formitor row on the Plugins screen, and on the Formitor settings page next to the version number. It checks immediately and tells you whether you're up to date or offers the update.
Automatic updates
On the Plugins screen you can click Enable auto-updates next to Formitor, and WordPress will install new releases for you within about a day.
The one-time step
This flow is built into the plugin, so a site needs to be on v0.2.9 or later before one-click updates work. If a site is older, update it once the manual way: download the latest zip from the hub's Plugin button and upload it under Plugins → Add New → Upload Plugin. Every update after that is one click.
Seeing versions at a glance
Your dashboard flags any site on an outdated plugin, and each site's Formitor settings page shows its installed version next to the Open hub button.