The Amazon Appstore's 'Wi-Fi Only' tag on certain large apps (read: Plants Vs. Zombies) has been a frustration for those with consistent access to 4G while they're on the go. I mean, come on Amazon, if I really want to download that 75MB PopCap game, it's my data connection! I'm sure there's some reasoning for this (like reducing the active # of connections on the Appstore's servers), but when you're on 4G, it only makes sense that you should be able to do the things you would on Wi-Fi.