Requires Unity 4.7.2 or higher.
Photon Unity Networking (PUN) Plus
• No Unity Pro license needed:
Export to all platforms, including iOS & Android
• Pay once - use for 60 month:
100 Concurrent User Cloud plan included.
PUN Plus is all you need to easily add multiplayer to your games and launch them globally with the included 100 concurrent user Photon Cloud plan.
Forget about hosting, connection issues and latency.
The ease-of-use of Unity's Networking plus the performance and reliability of the Photon Cloud.
Global low latency: Photon Cloud hosting centers in US, Europe, Asia (Singapore, Japan) & Australia provide low latency for your games all over the world.
Low learning curve: The PUN API is very similar to Unity's networking solution.
Always connects: Simply works across networks, no punchthrough issues.
Convertible: A script ports your Unity Networking project. 90% work: Done.
Integrated by top tools: Ultimate FPS (in closed beta) & Playmaker are both integrated with Photon
More info:
Unity Forum Thread and Product Website.