Jewish Calendar for Mac is a no-frills app that shows Jewish months, holidays, parshiot, and more. It's nothing fancy, but it's a great way to keep track of and print these important days and events.
Jewish Calendar for Mac's interface is plain and not especially attractive, but its simplicity makes it easy to navigate. Users can choose between Gregorian and Julian calendars, and each day is labeled with the current Jewish month. Users can also opt to have the calendar display parsha, Omer, and Chol Hamoed, and can switch between diaspora and Israeli calendars. There's no Help file, but that's not a significant drawback, as all of the app's features are easy to figure out. There may be more sophisticated programs that do the same things, but for a basic calendar, Jewish Calendar for Mac is perfectly adequate.
Jewish Calendar for Mac installs and uninstalls without issues.