Live from Appjam in London

We're liveblogging the mobile developer event with stats, stories and more.

Tonight, ME is attending Appjam, a gathering of mobile developers in London. It includes a presentation from metrics firm Distimo, a bunch of demos of new apps, and a panel discussion. We're liveblogging the first two - unfortunately, I'm on the panel, so it might seem rude to be typing at full pelt during that. Read on...

Remco van der Elzen is kicking off the night. He's co-founder and head of business development at Distimo, the app store analytics firm. He's going to dish a bunch of stats comparing different mobile app stores.

It tracks 24 app stores worldwide (shame on you if you thought there was only one), including those launched by device makers, operators and independent companies. The company collects data, and distributes free monthly reports on what's going on. Tonight's presentation is focusing on iPhone, BlackBerry and Android.

So, how many apps available? 100,000 on iPhone, 14,000 on Android, and 3,300 on BlackBerry App World. He expects this to change fast, as Android Market and BlackBerry App World pick up steam.

Pricing: 25% of iPhone apps are free, and 75% are paid. For Android the ratio is 63% free and 37% paid, while for BlackBerry it's 32% free and 68% paid. Why the difference for Android? "The approval process is less strict... so many people develop small applications that are maybe not worth paying for, so they distribute it for free. Also the payment is pretty difficult."

How much are people paying? BlackBerry is about three times as expensive as the other stores - possibly down to different demographics of users. But also because of the minimum price of $2.99, and the fact that a lot of companies making BlackBerry apps have been doing it for a long time before the App World launched, selling for fairly high prices.

But Elzen points out that prices are skewing towards $0.99. Why? Apple's ranking system is one reason: "It favours the cheaper applications. If you want to come in high in the paid app rankings, you have to be downloaded many many times. So almost always the number one ranked application is priced at 99 cents."

What about the Top Grossing chart for iPhone? Games do well here - 49% of the Top 100 Top Grossing apps are games. He moves onto a slide of the apps that are grossing the most (on iPhone) through in-app payments - games score highest here again, alongside a generic 'other' category. Social networking does well though - he cites an example of an app that lets people send virtual roses to their friends.

Now a slide on Content Refresh Rate. iPhone apps tend to spend 14 days in the top 100, compared to 26 days for Android, and 20 days for BlackBerry. There's more churn on iPhone in short. And that's a wrap. Now for the panel - after which I'll rejoin you for the app demos.

And we're bac k in the room. First demo is Topsee. I missed the first half of its presentation due to a toilet break, for which I apologise. It shows you "top things to see" in the city near you right now. No search - just a bunch of recommendations - a deliberate design decision.

People who contribute the content get a 50% share of the ad revenues - there are banners on the bottom of the screen supplied by AdMob. "We're hoping that by using this, you'll have a better time in the city that you're in." It's got a very nice multitouch interface too. At the moment, it's focused on London, with plans to expand.

Second up is SDGames with a preview of an iPhone game called Touch Soccer. It's a gesture-based first-person 3D football game. You can pass the ball around the pitch, do swanky kick-ups and tricks, with players that look like salt cellars with heads.

It looks good fun, and is due to be submitted this Friday. It used to be called Flick Football, but I'm guessing Freeverse (which makes Flick Fishing etc) put their foot down.

Third up, the marvellous RjDj. It's a music iPhone app. It's about bringing live produced music in real-time to someone's personal space - their iPhone. "Being able to generate and create music live, throughout your day, based on what's happening around you... The music has become software."

Yes. They show a video of singer-songwriter Imogen Heap being a bit airy-fairy about it, but really you should download it for yourself and listen to it on your commute to work. A hard app to explain in the flesh.

Next up is Rippll. An app that lets you see whether your friends are nearby, and if there are any two-for-one offers in the nearest high street. “We drop in these mobile coupons so you can reuse your Rippll social profile to redeem a coupon, find your friends and share vouchers”.

But it's also a publishing platform, so anybody can use Rippll to build their own app – a bar guide, a cinema app, even a dating app. The idea is they can all use Rippll's social engine. The company has published ten iPhone and Android apps, spanning social, travel and finance. It's also making branded apps that use location-based data – next week a London Star Map app launches for The Celebrity Planet.

“We need to get to the million user mark before we can approach the brands we really want to,” says the presenter. The iPhone app is out now, with Android following in a couple of weeks, alongside an augmented reality layer. Nice.

You want another app? You got it! Alamex is showing an app called iHi. I caught sight of it earlier tonight and downloaded it immediately. It's a “visual messaging device” for use in apps and bars – you show text-based messages on your iPhone screen like 'HI', 'DRINK?' 'BILL PLEASE' and 'IDIOT' (the last is for showing to other drivers.

There's a free version with 12 preloaded messages, and ...