Free with in-app purchases
Viber isn't big in some parts of the world. However, it's among the most popular messenger apps ever. It boasts a full experience, including messages, calls, a self-destruct chat, group chats, video messages, video chats, and more. It also includes some extras like stickers, worldwide news, and more. Most of the sticker packs cost extra, hence the in-app purchases. This is actually a fairly well-rounded chat experience. However, it is a little heavier than most chat apps.