After tinkering with the development of my first app for quite a while, I finally got it to a state where it all works so I submitted it to iTunes a couple of days ago. I now have to wait for an Apple reviewer to test it before it becomes available to the masses. Hopefully they won't find some trivial excuse to reject it!
It's an app for engineering unit conversion. Although there are several unit conversion apps already available on iTunes, they are mainly useful for everyday conversions to ensure your recipe tastes OK. Mine includes 77 unique dimensions with lots of engineer/scientist conversion categories such as viscosity, density, mass and volume flowrates, heat transfer coefficients, etc. It's priced at $0.99 mainly to see what the level of interest is for what I would call "serious apps" for engineers. If I get enough sales to cover my costs so far I have plans for other apps as well as extensions to this one. If you are interested, in finding out more before it appears on iTunes, the full description can be found on my website at: http://activeminds.ca/iphone.php
Because of the severe limitations of the iPhone screen size, I'll mainly be targeting future apps at the iPad. I firmly believe that tablets like the iPad is the way mainstream computing is heading and I intend to be out there near the front of developments. Most of my future apps will rely heavily on AJAX methods to communicate with a server for all the heavy lifting and use the iPad screen to present that information in a friendly fashion.
I mentioned somewhere else on this forum that one way of providing iPad apps is simply to reference dynamic AJAX websites and let the built in browser do the necessary display work. This works just fine of course but one of the odd things about the Apple marketplace is that users want specific apps that display data using native iDevice widgets so that it looks like it was specifically designed for the device. Since Apple users are prepared to pay extra for these apps, it behoves us as developers to pander to their whims. I don't really know why the market is skewed towards paid for apps but it's good for us developers because it provides a niche to re-present old websites as new apps with relatively little in the way of extra development work. Converting those apps in the future for other tablet devices as they appear is quite straightforward as all the server end code stays the same.
In the future, I wonder if a phenomenon similar to the Apple one will occur with more traditional computing hardware. Will users of regular computers be prepared to buy specific apps even if they can get the same information via their browser for free? There are certainly some advantages in getting internet access via an app rather than a browser, not least the protection of minors from some of the bad stuff out there. The closed nature of the platform also reduces the chances of introducing viruses and other malware.