Uses data from blockchain.info and returns a png progressbar for the current funding of the provided address. I had to shut down the online service for financial reasons but you can host it yourself very easily.
Include a bar showing progress towards a funding target like this:
<!-- example.com/$btc_address/$funding_target --> <img src=http://example.com/1MWdTySikEqszL6cUYDiZ6Xb9EutptMtFM/0.1>
Currently, this project just exports a express style middleware, that you can include in your own servers.