Does not work well with FF Private Window with enabled Tracking Protection. So, there is a few ways to make this addon work in Private Mode:
1. disable Tracking Protection and reload page.
2. disable Tracking Protection completely.

The reason, I suppose, addon uses iframe (not Google API) with mobile version of translator and this address in FF block-list.

Hi, This addon is very promising.
Still is it possible to add some customization options:
- ability to remove context menu item
- ability to trigger a pop-up icon after long mouse click instead of regular one?

Works as advertised!

Thank you very much for WebExtension porting.

EDIT: The context menu description it too long in my opinion making this too large.
For me is enough "Panel Translate View".
Thanks.