Go to either the Apple or Android App Store (depending on your phone) and search for Tapatalk. I know that on my iPad, if I open TB in Safari, a pop up telling me about Tapatalk comes up, with a button that takes one right to the Tapatalk page in App Store (doesn't matter that one has to use Safari for albums, groups, etc.)
I tried that and got lost without accomplishing anything. I seem to recall that Charlie had a link that stepped you through the process.
I actually got Tapatalk from the Amazon App Store rather than Google Play (for some reason that I don't recall). When you install it, just search for TrainBoard. What kind of phone did you get Russell? Charlie