Forum Runner's integration into vBulletin 4.1.12 empowers you to provide a lightweight and efficient mobile application for your online community. From its mobile-optimized screen display to its fast page rendering your users are able to browse and experience your forum with a quality comparable to that of a laptop or desktop computer. Push notifications keep your members "plugged in" and coming back to your site to review the content and conversations they have found most interesting. Photo uploading is streamlined into a simple process that makes it easier for your community to share and interact. Though all vBulletin forums can download the Forum Runner plug-in from forumrunner.com to use on their sites, the newest version of vBulletin gives you access to a 1-click activation of Forum Runner through your admin control panel. This activation allows your forum to benefit from these and other capabilities. (source email from vBulletin)
I tried their old mobile app, and was disappointed. Using the app, the site didn't refresh unless you quit out of the app and restarted it. It didn't attract any new users to the site, or result in any measurable bump in traffic. From the expense of buying the app, and paying Apple and Google to join their developer programs, it wasn't worth it. Now, I just tell my users to use Tapatalk.