The newer your BlackBerry, the more apps you use.

There are now 50 million BlackBerry users worldwide and 35 million of them are downloading more than 1.5 million apps per day - that's about one new app each every three weeks - and more than 75 per cent of those downloads are from handsets with the BlackBerry 5 and 6 OS's.

RIM is expecting that we'll get a lot more apps; and a lot more of what it calls super-apps that integrate with key features of the BlackBerry system like push content and inbox notifications - and now BlackBerry Messenger.

RIM's peer-to-peer instant messaging system already has 28 million users, and it's growing by 1.5 million users a month ("that's 2,000 new users an hour," points out CEO Mike Laziridis; "it's amazing.").

Apps and BlackBerry Messenger

The big news from the BlackBerry Devcon yesterday is that next spring apps will be able to plug in to BBM to send invitations (to play a game, say, or buy a ticket to the same concert), transfer music, photos, video, add contacts and groups of people, chat directly from the app – or add extra information about you like your gamer name or the music you're listening to or the last ebook you bought.

"If you open a contact in BBM," vice president Tyler Lessard told TechRadar, "it's one click to jump into an app that can provide more information about that user. Or for multi-player gaming, you could use BBM to invite other users to join a game and use BBM to do real time data transmission."

Magmic is going to use this to add social features to its BlackBerry games, Kik Music plans to use it for sharing what you're playing, Telmap will let you send messages with your location attached and the Kobo ebook service will let you share what you're reading.

Better and cheaper apps

Other announcements from the conference should mean more, better and cheaper apps for BlackBerry. Maybe because widgets sound like something simplistic, RIM is changing the name of its system for creating web-based apps that run on BlackBerry to WebWorks.

"You'll be able to create apps in days, if not hours; anyone who knows HTML can know build apps for BlackBerry," claimed Laziridis. Web apps will get access to all the BlackBerry tools, from sending text messages, showing rcent calls, playing media, integrating with the calendar and getting push information to running in the background as a true multi-tasking app.

RIM is still promising to offer carrier billing with more operators than just AT&T in the US, so you can buy apps or make payments within apps and pay for that as part of your monthly phone bill.

"We'll see more carriers by end of this year," Lessard told us "and many more carriers around the world over the course of 2011. By the end of this year RIM will also let apps offer micropayments, so you can get upgrades or buy new levels of a game or virtual currencies for social gaming.

Expect BlackBerry apps to have more ads as RIM launches its new ad service today, which will aggregate dozens of different mobile ad services from around the world, including mobile operators' own ad networks (although it starts with just five big names) and give developers a 60 per cent cut.

Location-based video ads

That should mean more apps being free – or at least cheaper – and you might even find them useful because ads can include links you can click to make a phone call, or get a map or watch a video or send an email or create an appointment in your calendar. Video ads will be available in the next few months, as well location-based ads based on Navteq's service.

"So if you get an ad for a restaurant," suggests Lessard, "you can put that right in your calendar and call to make the reservation and it will take the address details and everything, and put it right in there. Make it easy to integrate with apps; a nice little thing we like to call a superapp experience." As an added incentive, RIM is waiving developer fees for App World for what it calls "a limited time".