Android Marshmallow introduced a feature called Google Now on Tap, and it's been getting some serious upgrades in recent months.
By long pressing the home button on your Android M phone, you get contextual searches depending on what you're looking at. That includes finding a prominent name and giving you quick info about them, and it even works inside the camera app to look for familiar brands or things like book covers to keep you informed.
Now on Tap is constantly improving and the latest update brings along instant translation from any app or screen. If any foreign text is detected it will try to change it into the native language on your phone, which is a very convenient and fluid way of translating.
There's more including an integrated barcode and QR code scanner, which should really have been there before. The translate feature is currently available for phones with the language set to English, French, Italian, German, Spanish, Portuguese and Russian.