ICQ is a convenient and easy to use messenger service. Always be in touch with ICQ's features:

• securely encrypted calls
• high-quality video calls
• speech-to-text for voice messages
• ability to create your own stickers
• animated 3D masks and video calls
• livechats with unlimited participants and channels
• chat synchronization across all devices

And all these features are free and without ads!
From version ICQ — Video Calls & Chat Messenger 7.1(823051):
Hi all! We have some very noteworthy and important changes for you that will make our application easier to use.
New design for the chat list:
• message time shown
• status of outgoing private and group messages
New features:
• mark all chats read by pressing the ✔︎ button in the chat list
• change your phone number in the Settings
• mark a chat unread by clicking on the box
In the chat itself, there is now an avatar of the chat partner or group, icons have been updated.
All versions