4. Kik

Like WhatsApp, Kik has become an insanely popular messaging app for kids who like to chat.

It's just one of the other fast and intuitive messaging apps used as an alternative to SMS texting, requiring only a username rather than a phone number.

If you take a look on Instagram, you'll probably notice that a lot of profiles list their Kik usernames in their bios so that other Instagrammers have some kind of way to contact them privately.

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