Having had some success on Reddit, I thought I would clue you fine folks in on a mobile web app I made called DiabloAH.
Tired of Diablo 3's Auction House lacking some key features, I decided to create an app that mimics one of my favorite addons from WoW (specifically Auctioneer) that can be used on mobile devices.
Because there is no API for the Auction House, it does require you to provide some specific details about an item, but, once complete, offers rich features like Comparison Stats, Bid/Buyout Suggestions, and Market Research (a neat feature that compares your item against all other successful sales to determine it's worth).
Today, DiabloAH is much more powerful than the Excel Spreadsheet it began as and has helped me sell over 70 items and make a little under 1.5 million gold (and 4 dollars!) on the AH. And, as of this writing, is being used by hundreds of other players.
I do want to mention that this isn't a scam or anything like that. I'm hosting the app on my own dime. It does ask for an email address and password, but I don't do anything with them.
You can absolutely use a completely bogus email address and password as long as you remember it.
Please DO NOT use your BNET Account information. This app is standalone and does not connect to Blizzard's Servers.
More details about the app (as well as screenshots) can be found on it's "About" page:
Recent updates can be found on the "Latest Updates" page:
And, you are also welcome to read the reddit where I first announced the app by visiting:
I'll gladly answer any questions you might have about the app on here as well. I make little applications like this all the time, but I generally keep them private. This is the first one I sunk a large amount of time into and I wanted to share it. Not to mention, the more users it has, the better it becomes.