Last month, I worked on a little project bfsim-js, a portable graphical brainfuck interpreter, not foreseeing that some people would actually make suggestions and request for changes. Maybe because, as someone commented, I am star-struck, I have decided to further develop bfsim-js.
Watch out for updates!
(EDIT: Correction in the interpreter.)
Around half a year ago, I realized I wanted to write factorial in brainfuck, partly because I was bored and wanted a bit of a challenge, and also partly because I could interestingly call the code brainf*cktorial. It turned out, however, that I was not restless enough for code that used tape that my mental registers could not accommodate. At that time, I did not have a pen and paper, nor a computer, and it occurred to me that I wanted a graphical brainfuck interpreter. I finally wrote one this week.
The graphical brainfuck interpreter can be accessed here. JavaScript and Document Object Model (DOM) made development so much easier. It is pretty cool, so check it out.