Thank you guys for the info.
It's a shame though

Hello,

I've noticed the add-on for overriding New tab page got deleted recently:
https://addons.opera.com/en/extensions/details/custom-new-tab-page/?reports#feedback-container
It's still in Googles cache.

And it's author is still here:
https://addons.opera.com/en-gb/search/?developer=sanishmistry

Is there a way to get it back? I have it installed and it still works, it just can't be downloaded anymore.

I'm asking because I'm author of Group Speed Dial add-on and since my add-on is awaiting moderation since May 23, 2017 (!!!), this "Custom New Tab Page" was only way to get it properly work in Opera (after installing it from Chrome web store).

Thank you and happy new year!

You can also use "Custom New Tab Page" add-on to override New tab page with any URL, including your favorite add-on new tab page URL. I'm using it with my Group Speed Dial add-on and it works well.

https://addons.opera.com/en/extensions/details/custom-new-tab-page/