Joe is getting his first smartphone and he's looking at Walmart's StraightTalk which offers unlimited talk, text, and data. Leo says that unlimited doesn't necessarily mean true unlimited. After a few GBs, they'll throttle it down to an almost unusable speed. And StraightTalk is an MVNO through AT&T or Sprint. So he'll have to check what network he would be using, and what the coverage is like in his area.
Walmart will also have a great deal on the older phones as well. Does it come with games? Leo says that no, but he can download hundreds of games, and they're mostly free (called Freemium). He'll have to be careful because they charge for in-app purchases and those can really add up.
Leo also says that the HTC M8 is a nice phone but it's only on Verizon. Joe should also check out T-Mobile. They have a $30 unlimited web-only deal. It includes 100 minutes a month, so if he doesn't make many phone calls, that's a great bargain.