Excitera Mobile Cup: Ten steps to creating your first iPhone app

posted by jack at 03:04 CET in / compute / programming

Last night, I spoke at an iPhone-themed event hosted by Excitera as part of their Mobile Cup, presenting some information for "iPhone-curious" developers and entrepreneurs about the iPhone development process. I gave a non-technical presentation of the series of steps/tasks that any new iPhone developer will need to go through. The slides are available .

Aaron Ardiri also presented his experiences developing his series of games, and John Chang talked about some of the things he's dealt with working on Skype's iPhone app as well as some insights from his previous work at Apple. There will be some video available later, I'll post a link here when it's up!

Big thanks to Hannes Dernehl for arranging and hosting the event, and Cristobal Viedma for asking me to be a part of it!

New game released: Diabolotros

posted by jack at 07:44 CET in / compute / programming

Yesterday I released a new pair of games for iPhone and iPod touch in the App Store, Diabolotros and Diabolotros Lite. Diabolotros is a retro arcade shooter, most of the gameplay is lifted straight from classics like Space Invaders, but I've given it a few twists of my own, and added iPhonetastic tilt'n'shake controls: You tilt the device to steer your ship, and when you have special weapons available, you fire them by giving the the phone a little shake!

Things for you to see and do:

• Diabolotros info page
• Diabolotros "sneak preview" on YouTube from a few weeks ago
• Dave Mark's kind words about the game
• Purchase Diabolotros on the App Store
• Download Diabolotros Lite on the App Store

Scribattle Lite: More results

posted by jack at 12:22 CET in / compute / programming

Some time ago I posted some charts showing how my first iPhone game, Scribattle, was doing after the release of its free sibling, Scribattle Lite. It turns out that the game was at that time already nearing the heights of its popularity (but oh, what heights it hit!) The absolute peak occurred on March 3rd and 4th; during that 2-day period, the full version sold 800 copies and the free version was downloaded a quarter of a million times (that's 250,000 times).

The charts below show the progression of events after that. Unlike the previous charts, here I've chosen to include the actual numbers of sales and downloads, instead of just showing them in relative terms. In both charts you'll see a temporary sales up-swing, lasting about 5 days, from the 13th to the 18th of March; That's the time period I ran a "sale" on Scribattle, selling it for $0.99 instead of $2.99. It didn't impact my revenue much during those days (roughly triple the sales numbers, but each sale yielding in one-third the revenue), but it may have temporarily delayed the inevitable decline, since the increased sales numbers helped keep it in the charts a little longer.

The chart on the left is a plain linear plot of Scribattle purchase and Scribattle Lite free downloads, with the downloads for Scribattle Lite divided by 100. Without doing that division, you wouldn't see any difference in sales of Scribattle, just a solid blue line along the bottom, because the ratio of Scribattle purchases to Scribattle Lite downloads has normally hovered between 1:200 and 1:100. So, on the big peak day, March 3rd, Scribattle was bought 373 times, and Scribattle Lite was downloaded 131,000 times.

The chart on the right is the raw data (no dividing anything by 100), but this time plotted on a logarithmic scale. Doing this tends to flatten out the peaks, while at the same time accentuating the differences in the smaller ranges. Here you can more clearly see the nature of the "long tail" that Scribattle and Scribattle Lite are currently experiencing; free downloads and sales have both been holding pretty steady for about a month! Granted, I'd be happy to see the steady-state numbers be higher, but I really can't complain about it either.

One interesting spot in these graphs is April 9th. That's when I released an update to Scribattle Lite containing ads (they don't affect the gameplay, but instead turn up between levels every few minutes). Looking at the logarithmic chart, you may detect a slight spike in sales, followed by a slightly sharper decline, leading down to the current steady state a few days later. I'm not sure if this was caused by the inclusion of ads, or just happened anyway, but there it is.

I Can't Believe I'm Not a Millionaire

posted by jack at 09:12 CET in / compute / programming

Last night, I gave a presentation at the Stockholm Cocoaheads meeting entitled "I Can't Believe I'm Not a Millionaire"about my experiences with Scribattle and Scribattle Lite on the App Store. Scribattle Lite had a short but intense "hit" period when it reached the #1 or #2 spot in most countries, and has now been downloaded over 1.5 million times! See more in the slideshow.

Scribattle Lite: Initial results

posted by jack at 11:09 CET in / compute / programming

I've been collecting data for both Scribattle purchases and Scribattle Lite downloads, and have some results to share. Like most other reports of this nature that I've seen, I'm going to be coy and not show any precise numbers, but rather some graphs that show the relative growth for these products. These charts begin on February 10 (the day Scribattle first appeared on the App Store) and March 1. Blue dots are Scribattle, green dots are Scribattle Lite. Scribattle Lite was only available during the last five days of this period.

The first chart shows a nice rising slope for Scribattle Lite, and what seems to be a complete flatline for Scribattle. This is due to the fact that the free downloads completely dwarf the paid downloads, so that none of the changes in paid downloads equate to even a single pixel on this scale.

The second chart reveals the true growth in Scribattle sales by scaling them up to match the Scribattle Lite downloads. Basically, if you plotted Scribattle sales by themselves, and then overlaid that on top of a plot of Scribattle Lite downloads by themselves, this is what you would see.

Finally, for the sake of showing both sets of numbers relative to each other, while still allowing some viewing of the smaller values in the Scribattle sales, here are is a logarithmic view of the same data shown in the first chart. The nice straight rising lines toward the end, especially for Scribattle Lite, show periods of exponential growth. What you're seeing is basically a doubling of the number of Scribattle Lite downloads each of the last 4 days, and nearly the same kind of increase for Scribattle sales!

I've only had my Lite version on the App Store for 5 days, but even at this early stage I feel safe in saying that in my case, releasing a Lite version has been a huge win for sales of the full version. Not an epic win (yet), but still a huge win.