With just 7% of communication being attributed to spoken words, and the remainder down to body language and tone of voice, it’s easy to see why communicating online has been described as cold and impersonal. Emoticons, emoji and stickers are helping make digital communication a bit more human.

As young people flock to WhatsApp, LINE and other chat apps, Facebook struggles to stay relevant. In response, it's created better emoticons – called Stickers – that are part of a deeper shift towards pictures as a primary way to communicate.

"People think it's just an app that says 'Yo,'" Yo founder Arbel told the New York Times. "We like to call it context-based messaging.” Effectively, Yo really is just an app that says 'Yo'. So why has it already been used four million times and attracted $1 million of investment?

While WhatsApp wins over the West and WeChat conquers China, messaging app LINE has taken Japan by storm. With 400 million users worldwide, and 52 million in Japan alone, LINE's bright and vibrant customisable stickers are hugely popular – but can they really replace text?