Features

Include titles : Export Tabs URLs (ETU) provides a default format which displays titles along tabs URLs
Custom format : optionally, custom patterns can be defined instead of the default "include titles" one (e.g. markdown, html…)
Filter tabs : ETU provides a RegExp-enabled tabs filter
Limit to current window : optionally, the list can be limited to the current window
List non-HTTP(s) URLs : optionally, ETU can list each and every tab, including cases where the URL scheme isn't HTTP(s)
Ignore pinned tabs : optionally, ETU can ignore pinned tabs

Permissions

Access browser tabs : required to list the tabs ;
Input data to the clipboard : required to copy the list to the clipboard ;
Display notifications : not required stricto sensu (as the extension could work without it) but it is used to improve the user experience by providing visual feedback about what is going on ;
Storage : required to store settings.

How can you help improve this add-on?

improve the current German translation: it is currently a mix of human translation, computer generated translation and no translation at all. It would be great to have it fully translated to German by humans :-)
report bugs and issues on Github: the review section of the Firefox add-ons page is not the right medium to discuss about issues. If you want to make sure that an issue/bug is taken care of, please report it via proper channels.
If this addon is useful to you, give it a positive review and spread the word.

If you are not comfortable using Github, drop me a line, any help, in any form is welcome.