If you wish to consider supporting Android, here are some realtime statistics to help assess the value of opening that can of worms.
At the moment of this posting iOS devices are polling at 71.422%. One app provides access for 70 percent of the mobile devices in the world.
All versions of Android together make up just under 26%. So if you decide to deal with the morass that is Android fragmentation your reward is a fraction of a smaller part.
A smarter course, I would think, is to create a good mobile theme that automatically serves up based on browser version or via a top of page link. The mobile theme Chris uses at Conjure Nation is excellent on all five of the table/mobile devices I have. No need for an App if you have a well designed theme, and you are much less likely to have compatibility issues because of fragmentation. And the mobile theme will probably render the same on iOS devices so you'll get support for that without your users having to buy TapATalk. (You should support that anyway, since it's basically free to implemenet, and we TapATalk users like having our stuff in one tidy little box.)