How to translate the text "See the categories" and "See all tags"
Please, copy the file attached in the main root of ajax product filter plugin. In this way you can translate (by string translation) the two string in option panel:
Of course you can override this text by widget:
In this case you can use the admin text string translation. Go in WPML > String Translation and click in Translate texts in admin screens at the end of page:
In this page search the ajax product filter widget:
And you find the list of widget added:
Click on widget id and search for the text that you need to translate, enable it and click on Apply at the end of page:
Now, click again on string translation and you find the widget string: