you are doing nothing wrong. To my knowledge, there is no effective firewall app for android that doesn’t occupy the VPN connection. From my understanding, you either have a VPN or a firewall. I have found no work around for both that was effective.

Its honestly a coin toss. Great resource for finding books, don’t get me wrong, but its hit or miss if the book you want is in the right format for what you’re asking.

On the hiking note, it also shows a lot of trails. I used it to navigate to a trail head and was pleasantly surprised to see a rough outline of the trails I would be using plus some others I didn’t know were there.