Also missing is offline support. While Android users can download language packs for translating without a data connection, iOS users get no such luxury. Even though such language packs are typically huge, the capability is an important one that I hope makes its way to iOS devices soon.
While Google Translate certainly performs a solid job translating, what really makes it shine are the extra conveniences it offers. You can set Google Translate to automatically detect your input language for quicker translations. There's a handy button to interchange your input and output languages. The app automatically keeps a history of your translations, and lets you star any of them for easy access later (even when offline). Text-to-speech output is available for select languages, and can be a huge help when you're dealing with unfamiliar phonetics. And finally, the SMS translation feature can pull in any of your text conversations for quick processing. Overall, there are a lot of extras, all of which come in handy.
In sum, Google Translate is easy to use, can translate more than 60 languages, and offers a variety of input options, all of which makes it tough to beat. That said, it still needs some key additions to bring it closer in line with its Android counterpart.