This menulet makes it easier to use brew.sh.

For example, you need to manually check if some of your packages can be updated.

With Brewlet it's easy: if everything is working swimmingly, then you'll see the normal shadow  icon.

If updates are available to be installed, the icon will become colored,  , to get your attention – along with a notification if you wish.

Once clicked, you'll be able to upgrade your packages, among other options. In addition, Brewlet will periodically check the status of packages in the background, so you don't have to.