ProBLog's mobile app publishes to a fixed location "/mobile". Think of this as a "container" for mobile posted blogs.
To include these posts in your blog lists, simply set your problog_list block on your main blog page to search "everywhere", and to filter by the ProBlog Post page_type. While editing, you may want to change the list custom block view to "mobile" or "micro blog".
You also need to make sure that your root->files folder has a folder called "incoming" that is chmod'd to 777.
lastly, make sure that the user you want to post with is set as a "blog editor" by editing that users profile and making sure that it is "checked"
That's it! Blog away on the go!