Which firm looks set to be the next Snapchat?

Investors fund new apps in the hope they will catch on as a global phenomenon before the developers burn through their capital. So who’s getting close?

Snapchat stands almost alone as an app with a mass user base that, to date, hasn’t been snapped up. The threshold for breaking out used to be 100,000 downloads; now it has surged to the one million mark, which is still a dot in the eye of ...