Harbor Master HD is a fun and very addictive game that will keep you busy for a good long time. It's a lot like Flight Control except this time you don't handle airplanes, you handle boats instead. Your job is to navigate the boats around a busy harbor so they can smoothly dock in and out of the space without running into each other. Created by Imangi Studios, LLC, the game is a cool take on being a dock master. It was first released in 2010 and already won raves from gamers. Although the game is offered for free, there are additional maps that you can purchase for a small fee. Nevertheless, the current free map is enough to keep you busy for awhile.