No luck here. Rated 1 out of 5 stars

FF 24 and no context option.
I'll keep watch for an update that works...

Recheck

Hi I_am_a_Landstander,

Thanks for leaving the comment.

The context menu option is always there. Just remember that the option is available in the context menu, only when right clicked on a TEXT AREA field.
Please follow the screen shots. If you still cannot see the option, let me know your Firefox version and OS name & version.

No function Rated 1 out of 5 stars

Sorry, but i can't find the function to format. It is only one button in Menu/Extras, without function!

This review is for a previous version of the add-on (0.1b). 

Only in Text Areas

Hi interfile,

I have tested using FireFox 17.0.1 & I can format xmls in text areas.

You can only see the option, when you right click on a textarea.
If you have done so & could not see the option -- 'Format XML', please check if the addon is enabled & also try restarting Firefox or re-installing the addon.
If you still cannot see the option, please let me know your Firefox version & OS