Select the language at blog creation (like password plugin)

Hi, i've just joined this site and tried some plugins, they're awesome
I've a little request for a plugin: it's like this: https://premium.wpmudev.org/project/set-password-on-wordpress-mu-blog-creation
But instead of permit to select the password it should permit to select the language of the blog the user is gonna to create.
I think it's very similar to the password one