I know Firefox is not your browser of choice but recently Firefox has been [reimplementing Chrome's extension APIs](http://arewewebextensionsyet.com/). This makes porting Chrome extensions trivial. [I ported some of them](https://my.owndrive.com/index.php/s/aYxdp4X0KVmgxEg) but did not publish them since I am not the original author.
How to port:
1) Install [Chrome store foxified](https://addons.mozilla.org/en-US/firefox/addon/chrome-store-foxified/) in a Firefox instance. Preferably in [Firefox DevEdition](https://www.mozilla.org/en-US/firefox/developer/).
2) Sign up for [AMO](https://addons.mozilla.org/).
3) Visit your extension's [home page](https://chrome.google.com/webstore/detail/fearch/kalmlbhhgndofalfencmggfncedfajgj) in the Firefox.
4) [Add to Firefox](https://youtu.be/xjcFxH8enoU?t=132) & sign addon. Done.
If you do not pass the Mozilla code review or do not want to publish your addon on [AMO](https://addons.mozilla.org/) no problem: you can distribute them on your own web sites as an [unlisted addon](https://blog.mozilla.org/addons/2015/12/01/de-coupling-reviews-from-signing-unlisted-add-ons/) (Lastpass does this). You will need to sign your extension with [web-ext sign](https://developer.mozilla.org/en-US/Add-ons/WebExtensions/Getting_started_with_web-ext#Signing_your_WebExtension_for_distribution). The credentials for web-ext sign can be [generated here](https://addons.mozilla.org/en-US/developers/addon/api/key/).
[How many Chrome Extensions run in Firefox?](http://mckay.pub/2016-11-18-webextensions/)
I'm no expert in addons/extensions but I can try to thelp you if you have any questions.
[Original post is here](https://www.reddit.com/r/chrome/comments/5l41ry/dear_chrome_extension_devs_please_port_your/)