Why the extension is targeted for Chrome only! What is so difficult about porting it to Firefox? When you come up with a product for mass user consumption, please don't assume everybody use Chrome by default.

When a product is targeted for Windows only, that means the product doesn't make sense to run in Linux. But, if the product is applicable to Linux, and the person or company who developed didn't consider porting it to other platforms, then it is left to the pain of users to find the possibilities to make it run on Linux. Or pray god one day it will be available in Linux.

In case of Extension for browsers, it doesn't make sense for users if the extension says it is targeted for Chrome browser only. Also, most of the extensions developed are not open source, so users don't have a chance to taken an effort to make it run on other browsers.

Hope you consider porting your Extension to support other browsers as well.