its been an idea of mine since i first heard of the ipad, and researching said idea is what lead me to the rpgtool website. I'd love to see a way simpler version of this tool for use on an ipad that can connect with nearby people or a wifi network. It wouldnt need chat because everyone would be in the same room using it just for combat/optional dice/pdf's/character sheets/initiative and you would definitely have to make the UI much simpler and more synergistic (waaay less options, there are a ton of options your program has that (although are awesome for playing online) would be far beyond unnecessary for this application).
basics of what you will need:
1. it would be more popular and way more easy to use on an ipad if you exclusively used pre-drawn tiles (similar to the official DnD tiles or paizo's game mastery series of maps). instead of using sight blockers and fog of war, the dm can simply tap an eye button and then tap tiles or drag his finger to make a selection box to make entire rooms visible etc as they progress through a dungeon/catacomb/etc, or the DM could even build it as he goes for a on the fly kind of dungeon. You could also still use fog of war and just have it automatic, where you select your vision or light source , and that reveals your fog of war for anypart of a tile that you can see, you wont have to make sight blockers with this method because the maps aren't gigantic open fields they are dead space with tiles on them (and players can only see and move through tiles) so if there is a tile on the other side of some dead space, the players wont be able to see it until they visually find how to walk to it with connected tiles. The tiles would most likely have to be squares to best facilitate having pre-drawn tiles like this... I'm sorry "hex" people, i appreciate you but your just far outnumbered by "square" people from an industry standpoint.
2. pre-build templates of generic random encounters/taverns/etc. perhaps even allow maptool exporting to ipad as flat images? This will cut down some time and allow the DM to make good use of the power of a tile based system and have all the maps still look highly professional and artistic.
3. a variety of basic tokens (including geometric ones for monsters that are not yet represented). If it is possible to still make custom tokens for an ipad that might be worth investigating, but from a simplistic standpoint it would be more powerful to have a large variety of premade ones.
4. simpler drawing tool. pick a color, pick a size, and draw with your finger. this will be more for gesturing and drawing things not represented in tile form into the game. similar to how a sports caster draws over game highlights.
That's pretty much the basics of all you need to make it. I know there are a lot of details and some things are easier said than done but the technology has existed for a while now to make an awesome touch screen maptool, and i know my entire dnd group would rush out and buy an ipad if it meant reducing table top clutter! as it stand now we all play with laptops for our pdf's and sheets leaving less room for rolling out the map and less room to even see each others faces while we game haha! I'd shave my chest with a lawnmower to get software like this and i know i'm not alone
I have a bunch of hand drawn mock up UI's already that i think would be both simple and successful.