How can I see IPhone emoticons on Twitter on my computer/android device?

[Edward]

Is there some sort of app or plug-in I can download? It's rather bothersome to always see those little squares and be left in the dark on their meaning.

[José]

Unfortunately you can't. Those iPhone emoticons can only be viewed by other iPhone's/iPod Touch's/iPad's. If you want to use emoticons on other programs like Skype, that have emoticons provided you can see it on other devices as long as you use Skype's emoticons and not your iPhone's.