I cannot specifically answer as to whether or not it will work with Walmarts plan as I have never tried it. I have used it probably around 100 times in different places and have never had a problem though. Personally I can't wee why it wouldn't work with a Walmart plan but I can't guarantee it
I've used mine with virgin mobile monthly wireless plan without a problem. The most important thing in my opinion is to make sure you have a good data plan to dowload your apps and updates and view all your content. I would recommend an unlimited plan or one with a 3G or higher limit. All the best.