Mumble - Mumble is an open source, low-latency, high quality voice chat software primarily intended for use...

GBWhatsapp - GBWhatsApp is a similar version for WhatsApp Plus have many new features

Discord - Step up your game with a modern voice & text chat app. Crystal clear voice, multiple server and channel support, mobile apps, and more.

WaStat – WhatsApp tracker - WaStat – WhatsApp tracker app shows the last online time of a phone number at a glance, so you can contact them whenever they get online to share something important to them.

RaidCall - Free & Light. Setting up is fast and easy; with no need to rent or set up servers. Low CPU usage and minimum memory footprint allows for smooth, uninterrupted communication. im. Group Communication.

Whatsdog Last Seen - Whatsdog Last Seen app shows the accurate last online time of all the phone numbers in your contact list to message them right on time and get an instant reply from them.