Following a series of attacks that took place in Paris on Friday evening, Google has announced that calls made to France using Hangouts will be free of charge. Google announced the move in a Google+ post expressing solidarity with France:
We're thinking of you, Paris. No fees on calls to France, via Hangouts. #ParisAttacks
Free calls from Hangouts include those made from the web, Android, and iOS. If you need to, you can find Hangouts for Android on Google Play.