Summarize:

You can get it for free from your mobile device's app store. There are several ways you can enter something to be translated:  Type - Touch the field to type in text to be translated. You will see the translation appear as you type. Camera - Tap the Camera button to take a picture of text to be translated. Google Translate will attempt to scan the text and then translate it, so make sure you hold your camera steady. Speech - Tap the Microphone button to speak a phrase that you want translated. Handwriting - Tap the Squiggle button to draw characters with your finger. This is useful for non-Latin characters. After entering your text to be translated, you'll see the result appear. Tap the "→" button to load the translation in the main interface. You'll see the Latin characters if applicable, and you can tap the Star to add the translation to your Phrasebook. A Dictionary card will appear for most phrases as well.
Download the Google Translate app. Decide how you want to input text. Accept a translation.