For translating foreign languages
Google Translate is improving all the time, and offers translations of 100-plus languages. Garbled translations are rarer now, and the app also offers instant translations when you point a camera phone at a street sign.
TripLingo minimizes miscommunications of all kinds for global travelers. It offers translations in 42 languages, guidelines on local customs, access to live human translators, and a great way to decipher dining receipts.
Microsoft Translator is particularly good at translating multiple tongues at once, making it ideal for group conversations. Participants follow along using their phones.
Waygo is indispensable if you plan to travel in Asia. Its developers pioneered the image-based translation of Chinese hanzi, Japanese kanji, and Korean hanja characters.
iTranslate is great for casual conversations. It can translate and vocalize in 24 languages whatever message you type in.