When writing initial HTML for something you often need some placeholder images. Then you normally go to some placeholder image service or download an image, copy it into you app file system and figuring out the correct path to it.
To ease this process I wrote a little tool in order to generate simple base64 encoded placeholder images. Currently can specify the image dimension and some font-settings for the image size description. The base64 encoded image representation enables you to insert this image directly as a Data Uri into the src (<img> tag) or url (css statement) of your document. Inlining the image comes with the big advantage that you don’t rely on the availability of the external service.
Go here for the tool: http://zhongdeliu.github.io/placeholder-image/
(Also the first time I used GitHub Pages btw.)