Create Firefox Add On

hi, I would like to create a firefox add on and possibly a Chrome extension for the same purpose. The idea is to connect content from web pages with content published on marketplace. Let's use this posting for example. The title of this job is "Create Firefox Add On", I'm looking for an add-on that will change the font type and characteristics to highlight this text in any web content that the user with the add on views. Also I would like this particular phrase to be linked to this page. Please bid only if you've created add ons before (samples). Thanks.