Alexander Isora 🦄- Founder @ Unicorn PlatformChatra is very affordable and powerful software, I recommend it.
Prasad Lingawar- Growth @ PlivoI consider this as a good free alternative to Intercom. Definitely better than Tawk and Olark.
SifteryChatra is just a modern take on messaging, more akin to modern mobile messengers. It's light, fast, beautiful and comes with all the bells and whistles small businesses would need AND a robust, well-documented API that allows for fine tuning.