Cacher is the code snippet organizer for pro developers

Urban Airship

http://urbanairship.com/products/mobile-app-engagement

Push IO

http://push.io/

Parse

• https://www.parse.com/plans
• Free plan - 1 million unique recipients per month. You can send multiple messages to the same device and that is still only 1 recipient.
• $0.05 per 1,000 recipeints extra.
• FAQ - https://parse.com/plans/faq/

Amazon SNS

• https://aws.amazon.com/sns/
• First 1 million messages are free - https://aws.amazon.com/sns/pricing/

http://www.kinvey.com/pricing

• Free plan includes 5 million push notifications per month