CheckUp is an easy-to-use multipurpose maintenance utility that can help you monitor and improve your Mac's performance. Its very visual interface uses colorful and dynamic icons, graphs, and dials to display performance and data over eight different categories: Profile (including uptime and a bandwidth tally), System (especially great for seeing which OS your Mac can handle), Processors (twin dials for dual processors, plus a temperature monitor), Memory (configuration, usage, and testing), Disks (all partitions, with an option for repairing permissions), Network (showing input and output in a customizable graph), Processes (a prettier, more flexible version of OS X's built-in Activity Monitor), and Documents (in which you can view docs by type, as well as search for and delete duplicates).
Much of this functionality can be found in the Mac OS, as well as in various other third-party apps, but CheckUp does an excellent job of combining and presenting all of it in a way that's easy, accessible, and safe, especially for novice users, with nice touches like an uninstaller. CheckUp even displays details on how to fix issues found on your Mac at launch.
Recent updates have improved CheckUp's ability to detect common issues and added support for the newest Macs and Mac OS. Unfortunately, CheckUp does not offer a fully functional trial, so it's difficult to evaluate many of its features, including the ability to optimize processor performance, uninstall apps, or run a full RAM test. Overall, though, its easy-to-use features and visually appealing layout make this an attractive option for a Mac maintenance utility.