If you don't hide your Dock, you've probably got wasted space sitting on either side of it. Docktor fills it with widgets you actually glance at: music, calendar, weather, system stats and more coming soon.
No extra menu-bar icon fighting for room. No separate window to open. Just the stuff you check constantly, parked in space your Mac was already wasting.
It also adds hover previews to your Dock — mouse over an app and see its open windows without clicking.