Forget Facebook, Twitter and SnapChat. One of these IM apps could be the next big thing.
WhatsApp Messenger holds top spot
An app that lets people exchange messages without having to pay for an SMS has topped the charts
The instant messaging system WhatsApp Messenger has continued its massive popularity, holding on to the top spot on the paid-for iPhone app chart this week.
The app allows cross-platform mobile messaging that lets people exchange messages without having to pay for an SMS.
On the iPad, the space combat game Galaxy on Fire 2 HD has moved into the number one spot, pushing last week's chart topper, The Living Earth world clock, into the number two position.
But last week's top free app for the iPhone - the mining game Gold Digger - has dropped out of the top 10.
What's My IQ? has stepped up to the top spot as the most popular free iPhone app this week.
The same free app appears at number two in the iPad chart.
The Simpsons: Tapped Out has claimed the top free app spot on the iPad chart just days after it was relaunched.
Among the apps forcing their way in the Apple charts this week are the vintage filter design application Vintique on the iPhone and Monopoly on the iPad.