1. WhatsApp: With over 2 billion users, WhatsApp is the most popular instant messaging platform globally. It offers end-to-end encryption, voice and video calls, and a simple interface that is compatible with nearly all devices.

2. Telegram: Telegram is known for its security and privacy features, such as secret chats with end-to-end encryption and self-destructing messages. It also supports large groups and channels, allowing users to broadcast messages to a massive audience.

3. Facebook Messenger: Integrated with the Facebook social network, Messenger allows users to send text messages, make voice and video calls, and share files with ease. Additional features include group chats, chatbots, and third-party app integration.

4. Slack: Slack is a team-oriented instant messaging platform offering seamless communication within an organization or team members. It comes with file-sharing capabilities, integration with various productivity tools, and threaded conversations for organized chats.

5. Viber: Viber offers free text messaging and high-quality voice and video calls over Wi-Fi or mobile data networks. It includes features like public accounts for businesses, stickers and GIFs for creative messaging, and end-to-end encryption for privacy.

6. WeChat: Originating from China, this instant messaging app has evolved into a multi-purpose platform offering voice and video calls, payment services, mini-games, official accounts for businesses/news/media sources, and much more.

7. Signal: With an emphasis on privacy and security, Signal provides end-to-end encrypted messaging along with voice and video calls. The open-source nature of the app offers transparency while supporting disappearing messages for an extra layer of privacy.

8. Microsoft Teams: Integrated within the Microsoft Office 365 suite of applications, Teams is designed for business-oriented collaboration offering chat capabilities alongside file-sharing options & integrations with other Microsoft software like Word & Excel.

9. Line: Popular in Asia, Line offers instant messaging, voice and video calls, stickers, games, and a personal timeline feature. With a vast array of services, Line has something for everyone, including a taxi booking service and mobile payment system.

10. Discord: Primarily designed for gamers, Discord offers voice, video, and text communication between users in a chat channel format. With customizable servers & channels, it has also become popular among various communities as a central platform for communication.