The first 10,000 minutes of voice chat each month with Agora is free, with no player limit.
Sign up for Agora: http://agora.io/
Agora on the Unity Asset Store: https://assetstore.unity.com/packages...
Source Code: https://github.com/RugbugRedfern/Agor...
Music by Stevia Sphere: https://steviasphere.bandcamp.com/