I signed up for the Bluebird account when they were originally doubling the Savings Catcher amounts if you transferred to Bluebird - so that's basically like a debit card that I have been able to use to purchase items including gift cards at Walmart. I do not know if it would work at Sams Club.
I believe you can use it with just the savings catcher money. I bought something else with the savings catcher gift card and it works just like a walmart gift card. You should be able to use it for anything they sell in Walmart.