Joe is frustrated because video is constantly buffering on his phone. Leo says it could be the phone. Older hardware has to work harder to play hi-res video. But more likely, it's Joe's carrier, which can have limited bandwidth. Since Joe is using Sprint, they've been late in coming to the LTE party, and it may be that LTE isn't available in Joe's area. An older phone, like an iPhone 4, won't even support LTE. A new phone will help, but Joe should make sure LTE is supported in his area.
Kris would like to move her iPhone 4 from AT&T to Verizon. Leo says she can't. The phones are the same model, but the iPhone 4 on AT&T has a GSM radio, and the Verizon model uses CDMA. She could get it unlocked and use it on T-Mobile, though. But to go from AT&T to Verizon, she'll need an iPhone 5 or above. In fact, if she can go to Verizon and say she wants to leave AT&T. Verizon actually sells an unlocked iPhone due to a consent decree with the federal government. And then she could use it on any carrier.
Google Maps has disappeared from her iPhone 4. She really likes street view, and would like that functionality back. Leo says that Google will be releasing a maps app for iOS. Apple replaced Google Maps with their own a few months ago, and it'll only be a matter of time.
Alex uses an iPhone 4 on AT&T and over the past couple of months, his reception has gotten so bad it doesn't work where he lives anymore. AT&T sold him a MicroCell to boost his signal but that doesn't help him when he leaves his house. Leo suggests asking people in his area what they use for their carrier, and maybe he could switch to something else.