We'll create fresh WordPress site with MslsMenu installed. You have 20 minutes to test the plugin after that site we'll be deleted.
Most people are likely to use some lines of PHP or the widget provided by the Multisite Language Switcher to integrate the links to the translations in their blogs.
But this can lead to fatal errors if you don’t know much about PHP, or maybe the dynamic sidebars are not the best place in your opinion. If you want to integrate the Multisite Language Switcher in one (or more) of your Navigation Menu(s) then you should give MslsMenu a try.