With all of the retail giants out there, I'm really surprised that Walmart is this late to the game in releasing its Android app. I guess the old saying "better late than never" applies here just as much as anywhere else, and any app that makes our lives easier is always a welcome addition in my book.
The Walmart app offers up all of the goodies that you need to shop-on-the-go, like deals, recent price drops, search, and store locator (including a filter to find stores with specific departments, like pharmacy). It goes a bit further than other apps of this type, though, serving up the local ad with a single tap, order tracking, and a front-end to the pharmacy. There's also a nifty Value of the Day feature that showcases a single deal everyday, similar to Woot (although much less entertaining).
The one downfall that I found in this app during the 30 seconds that I used it this morning was the lack of built-in ordering. Instead of going through the ordering process directly within the app, it redirects you to the full (not even mobile) Walmart site, which almost takes the point away from using an app in my opinion.
I don't want to be too harsh, though, as this is the initial release of the app. Even though it's missing what I think is a key feature, it's still a very useful app with a very intuitive interface. You can grab it for free in the Android Market.