Very, very useful and helpful for all Tumblr users. Missing E enables you to make the most out of Tumblr - you can shuffle your queue, add tags to asks, and set defaults for tags, etc. to make posting, tagging, replying, and asking much easier. I recently uninstalled Missing E and it goes without saying that it was very inconvenient - I had to go back and edit published asks to tag the user who asked me the question, publishing submitted posts was inefficient since the publish option wasn't next to the 'submit' button as Missing E changes it to, and sending asks required that I actually went to someone's ask page instead of being able to open a pop-up box from the dashboard quickly. Additionally, one of the best features of Missing E, in my opinion, is the quick reblog option. You can simply hover over the reblog button and can type the tags and caption there from your dashboard without being re-directed, you can change which blog the post is published on, and you can save the post as a draft or put it in your queue immediately; all without the hassle of having to open new tabs or being required to load a new page. Missing E also updates frequently to work well with Tumblr's current layout/interface, so it is constantly improving and becoming more and more helpful to all users of Tumblr.