How to translate and edit text strings in the XFtoWP plugin
XFtoWP is ready to translate from the Edit Strings screen and can be accessed any time from the admin settings page.

All text strings in the plugin are listed in the xfwp_strings
filter and the Edit strings screen allows you to translate static text strings that are used on the frontend of your site.
If you are creating an addon plugin for XFtoWP you can add your own strings to this interface with the xfwp_can_translate
filter.