A MacOS menu bar app for the phases of the moon. LunaMac calculates the current moon phase using your computer's system time. If the menu bar icon is a Ⓧ, something went wrong and LunaMac couldn't calculate the moon phase. You can try reloading from the icon's menu.
There are some useful implementations for those new to Apple's programming paradigms. Swift adopts a lot of Objective-C concepts, which themselves are likely foreign if you don't already have a working knowledge of Objective-C.