Cheng Hing used to be an investment banker, so he knows how working long hours makes getting friends together to attend an event frustrating.

"It was a painful experience asking friends on WhatsApp groups or Facebook whether they'd like to go to, for example, an exhibition together. Especially when not everyone is into the same kind of event," says Cheng.

What was needed, he decided, was a social networking app-cum-events directory for Hong Kong. The result is Playroll, a free app that connects to Facebook.

Playroll's chief function is to gather a crowd by allowing users to see who among their friends is interested in attending a specific event. The app is better than a listings magazine, says Cheng, because it is interactive. And it trumps Facebook by providing a central directory of events. With Facebook, if you haven't subscribed to a certain fan page, there is a good chance you'll miss the events listed on it.

The app offers "Playroll picks" on the front page and users can customise their preferences, or choose from categories such as "artsy" and "outdoor".

"What we're trying to do is handpick the fun events and fun stuff to do for young professionals in Hong Kong. At the same time, we integrate it with the social-networking function on Facebook so you get an alert if a friend also likes an event. It gives people more incentives to go to an event," says Cheng.

Playroll, which also features chat rooms where like-minded people can make friends and post links to ticketing sites, is free but only available for iOS devices for now. An Android version is scheduled to be ready in two months.