Well, after two weeks of using the app and checking the web site, I've determined that for me, both are worthless at helping me find .22lr ammo. Checking the app I've never found a time when the status went to "available" or "in stock". The best you get is "availability unknown". I thought if I watched the app and found it going from out of stock to availability unknown, I'd know the store had ammo, but that never really happened. When I go to the site, I can see why. If I search on .22lr, it says not available in my local store. When I click on "find in another store", it shows other stores. However, there is a status statement on the site that says something like "updated on such and such date and time". Problem is, that status changed about twice in the two weeks I was looking at it and when it did, it was at about 11am.
I think everyone knows, there's no .22lr in Walmart at 11am. Also, that status didn't change at 11am. It changed later in the day and said as of 11am. So even if it was accurate at 11am, you wouldn't know it until it's too late.
Therefore, I've resigned myself to the last alternative. I'm going to stop at a Walmart on my way to work every morning until I get some. I figure my best bet is to be there around 6:45 and talk to the "regulars" and figure out how to get some ammo. All the clerks I've talked to have been very nice and have all said what others have said in this thread - that they get ammo on the truck at 10pm and someone puts it out at 7am. They also say that they are getting it pretty regularly which, getting back to the app and web site, is not consistent with their app or web site inventory.
Wish me luck! If I could get three bricks of anything so I'd have about 1,000 to 1,500 rounds, I'd be really happy.