by Jakub Suder, 3 March 2010

I became interested in iPhone development last winter, when I bought my own iPhone. I wanted to learn how to write iPhone apps, and the best way to learn how to program is to do it – so I needed to write a first simple application, that I could learn and experiment on. I've decided to write an iPhone client for our RubyTime service; I figured it would save me a few minutes each day if I could enter my activity entries while waiting for a bus on a bus stop instead of doing it in a hurry in the office before I leave (of course, I could also do it using mobile Safari, but it wouldn't be as convenient… and it wouldn't be so fun!).

The first version was ready a few months later – it was able to display recent activities and add new ones. I used and extended the JSON API that Marcin Kulik has earlier created when he was working on his RubyTime plasmoid for KDE4. I showed the app to Paul and he liked it so much that he allowed me to spend almost a month of my working time on improving it and adding new features. I've added support for admin accounts, to let Paul check on his iPhone who was busy and who wasn't, and for client accounts, so that our clients who have iPhones can monitor the progress of their projects. I've also added a search form that finds activities within a certain time range for given projects and users.

It took a bit longer than expected to bring the application to the point when it can be publicly released, also because we had to make sure that potential users can download a stable version of the server that supports the client app; but the release finally happened last month. I was surprised how fast the application went through the review process – I had heard stories of apps waiting for weeks or months to get accepted; mine was ready in less than 3 days!

If you want to try it, iRubyTime is available on the AppStore for free. I've also shared the source code of the app on GitHub, so if you're learning Cocoa and iPhone SDK, you can take a look at it and use it as an example or starting point for your own projects.

I must say that working on your first iPhone application is very difficult at first. It's a completely different experience than working on a Rails webapp – partially because of the language (ObjC), but also because of different approach and paradigms used in mobile app development, and because of limitations of the phone's hardware. I had to fix hundreds of strange and confusing bugs – but that means I've also learned a lot, and it will be easier next time.