I found an alternative that works with FF57 Rated 5 out of 5 stars
This was one of the best "install and forget" add-ons I have used. Unfortunately it doesn't work with the newer versions of Firefox. If the author doesn't decide to update it here is another add-on that works in FF57:
It's still working with Firefox 55.0.3 64bit Rated 5 out of 5 stars
But please think about convert this extension to WebExtension Ver.
It is near the deadline when we can not use this again.
Please Update Rated 3 out of 5 stars
Please update to work with Firefox 57
Nice little utility addon Rated 5 out of 5 stars
Not sure why some users are complaining that this addon is not working. Works perfectly in firefox 55.0 64 bit. Cheers
not working anymore. Rated 1 out of 5 stars
Should be removed from the store.
Doesn't work, please update Rated 5 out of 5 stars
Doesn't work anymore with FF 54. I beg you to update. No other add-on can replace this. I often found myself double-clicking things and not have them opened in new tab :(This user has 2 previous reviews of this add-on.
A Must Have Rated 5 out of 5 stars
I'm using this for years. It's a must have addon!!!
(Most of Piro's addons are!!!)
Hope it gets ported to Web Extensions!!!
Intended Webextensions compatibility. Rated 5 out of 5 stars
Thank you SO MUCH Piro. This is one of my favourite add-ons and has helped me a lot. IMHO its a "must have" Add-on.
I hope to use it after FF 57. Any plans to port it to webextensions?
Firefox51.0.1で動きません Rated 4 out of 5 stars
必須アイテム！ Rated 5 out of 5 stars
Nightly 55.0a1 Rated 5 out of 5 stars
Not working on nightly - the last few versions.
некорректная работа Rated 5 out of 5 stars
после двойного клика открываются сразу 2 вкладки
Very good addons Rated 5 out of 5 stars
Very good & helpfulThis user has a previous review of this add-on.
Essential addon Rated 5 out of 5 stars
There are tons of unlinked URLs on the web, in chats, on forums, in comments, etc.
The pleasure comes from small things like this Rated 5 out of 5 stars
I cant belive how usefull this thing is,it feels like luxury, i like it very much.
Not working on FF 48 Rated 5 out of 5 stars
This is a very useful app, could you update it to work on Firefox 48?
V 5.0.2016031501 Rated 4 out of 5 stars
Doesn't work anymore after FF V 48.0 (worked before using xpinstall.signatures.required to false in about:config)
Though, need an update now !!!
地味に便利 Rated 5 out of 5 stars
Not working anymore Rated 1 out of 5 stars
On Firefox 43 it opens strange Links instead of the clicked links. I switched to URL Links now.
Before it was very good.
Works good on firefox 43.0.1 Rated 5 out of 5 stars
Needs to be signed by developer to use on firefox 43.0, but after updating Firefox to 43.0.1 it works again. I download it from official site, not from addons.mozilla.org if it matters.This review is for a previous version of the add-on (5.0.2015060501). This user has a previous review of this add-on.