PixelSugar will prompt you to check for updates automatically, and if you opt-in to automatic updates, PixelSugar will notify you whenever there's an update you're eligible to install.
Manually Checking For Updates
You can also check for updates manually, by choosing Check For Updates... from the PixelSugar menu in the app.
Finally, you can always download the latest version and do a fresh installation. There are 3 places you can get the current version of PixelSugar: