For Android smartphones, the SBO forums look good and work great also with Firefox, Opera, Opera Mini and even the no-name browser that came as firmware on my LG phone.Sorry, ForumRunner probably isn't being updated anymore, either. Using Safari or Chrome and creating a desktop icon really is the best way to go.
And up until a few months ago, I was using a Windows phone. (Only about 2-3% of smartphones are running on Microsoft Windows mobile... I tend to choose the opposite of the crowd. Just like the decision to buy my boat. Only a couple of hundred 1980-82 Cherubini Hunter 36's were built.) SBO also ran/looked fine with Microsoft's Edge for Mobile.
Virtually all the features of the original app -- and also the desktop version -- are there on the mobile browser SBO webpage. And its almost as easy to navigate and use. Just got to get used to a slightly different interface.