MindMeister Quick Access is a free add-on for the Google Chrome browser that lets you access your existing mind maps as well as create new mind maps quickly, without having to open MindMeister's web app first.
To get the add-on, visit MindMeister in the Google Chrome Web Store and click on "Add to Chrome". Once the add-on is installed, a small MindMeister symbol will appear on the right side of your browser bar. Click on the symbol to open the add-on. When opening it for the first time, you will need to login with your MindMeister credentials.
To open one of your existing mind maps, click on the MindMeister symbol and type the map's title (or a part of it) into the search field, then select your map from the search results.
To create a new mind map, click on the MindMeister symbol and then select "New Mind Map".