Well, a number of users prior to the arrival of Generation 6 used a tool online called the Marriland Team Builder. However, now that there are new type mechanics with the introduction of Fairy and now Steel getting less resistances than usual, it threw that Team Builder out of wack and now battlers like myself and many others have been frustrated without it. Anyways, wouldn't it be kewl if we had one ourselves :D? Not only would it help users on this site, it might even attract others :0!
I don't know if this is hard to make, because I don't get that cryptic code crap, but I'm sure its about as simple as the Coverage Checker. Although I kind of feel like I'm pushing it, you should probably update this.
Here's the Marriland Team Builder. If you try it out, you'll notice it isn't up to date.
Anyway, obligatory Snorlax: