Browser extensions are an extremely under-used platform for Flutter developers. Extensions can be used as a supplement to any other platform and with a few tweaks, can take advantage of the power of Flutter by keeping to just one code base. In this talk I'll demo a real world use-case and then go over an example build with some key code components. I'll be covering the major pros and cons of using Flutter with an extension, how to work with browser APIs (including important JavaScript interops), tips on debugging, and best practices.