Showing dynamic text in another language

You can change the text for all of the widgets:

Navigate to Languages > (select a language) > Text on your dashboard.
But some of the text (button names, filter names, marker names, location custom text, contact info prefixes, etc) are dynamic and don't have a predefined text property.To change those:

Navigate to Languages > (select a language) > Rewrite rules.
Create a new rewrite rule for that language. For example, you could enter "my marker" in the left box, and "mon marqueur" in the right box. Now if you have a marker named "my marker", it will be displayed as "mon marqueur" in Marker Legend whenever French language is applied.