So I finally got around to publishing a tool I made for the WindowsPhone on the marketplace.
I've been writing little tools for myself for awhile now, but the marketplace is a little thin when it comes to tools for Magic the Gathering. I tried a couple of the tools there out and didn't really like how the interface/features worked and decided to write one for myself.
Anywho, it's called MTG Buddy, it's available on the marketplace now and you can buy it for .99 cents if you want here: http://www.microsoft.com/windowsphone//s?appid=550219d5-e78a-442c-807e-cf4eb26188a4
Putting it together wasn't all that difficult - I think the most frustrating part was dealing with the myriad of APIs and stuff available for getting card data. In the end I put together my own web service and database so I wouldn't have to worry about things disappearing or breaking.
I'm looking forward to the 7.5 release as they'll allow you to have databases in IsolatedStorage - converting jpegs to byte arrays and back is costly and so is storing those byte arrays in memory!