Try uninstalling and reinstalling the app. Since your top-level collection is all articles you're hitting the problem where we don't have a way to show the update is available in that case.
You need to build out your hierarchy. If you want other articles/collections to show up, add them either to the top-level collection or to other collections within it. They nest, like folders and files on your computer.
The update button will appear on the browse page for any collection in your system. You'll only hit snags if your top level collection consists completely of articles. We suggest having at least one collection in the top level to provide a place for updates to happen.
I've done that before but this time it worked. Bad news. DPS no longer supports the little guy. Only the Enterprise Edition is now available to use. Its only $25,000. Thats rude.