Any Android phone (at least the ones running Jelly Bean and newer) can send and receive emoji's. I'm not sure about older phones running ICS and older? But emoji's is built in to Android now. I can add them to gmail, G+, this forum, etc... Using the stock keyboard, you see the enter/return key at the bottom? Hold it down and the emoji icon will pop up and be selectable to add emoji's to whatever you are typing.
And I have an iPOd 4th gen (same as the 3GS) running 6.1.3. It is a serious lag fest. It can run a lot of things smoothly, but some apps can take several seconds to register and load, some apps (Nike Running app for one) will just force close for no reason, some apps freeze and I have to hit the home button, web pages take a long time to load. (And before you ask, I don't put hardly any apps, vids or music on my iPod. It has 10GB free. And it has been reset to attempt to fix the lag by both myself and via appt at the Apple store. It is in perfect shape, just can't handle the newer OS version. Wish I could revert it to iOS4 or upgrade to iOS7 (but alas, Apple will not let us upgrade to the latest and greatest.)
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Oh cool! I wouldn't know about Jellybean phones being able to do emojis because I don't really have access to one. But that's a cool feature.
Also, my dad's old iPhone 3GS, which is still being used as an iPod, runs 6.1.3 and it works pretty well. But a year with a low end Android phone has changed my idea of lag completely, so really anything seems better by comparison.