It can act on any web page you are viewing on your browser to give comfortable surfing.
We have created one bookmarklet for our client which can extract all images from the currenly displaying webpage and we can send those images to our server.
For more details about this bookmarklet project you can refer our website.
Another bookmarklet will allow the user to do search after completing customized algorithm.
You can contact us (firstname.lastname@example.org) for any of your software/web development needs.
You can see some sample bookmarklets here