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Category Archives: DDG

Image Retweever® App, “… a Lava Lamp for tweets,” is out the door.

Our new app, Image Retweever® App, is now available in the iTunes App Store. Our marketing site is This fun app is built on top of the library engine we built for #Chat. Stay tuned for more technical details soon. I must do some marketing first.

An iTunes App Store App Review Success Story

My new app Startup Crawl,, was just approved by the Apple App Review team. This is unremarkable and expected for a simple app. What is remarkable was how well and simple getting this app approved using the expedited review request proved to be. Startup Crawl is a simple event directory app supporting the Startup […]

A Pattern to Declare an Objective-C Mix-in

The missing piece for creating a full fledged mix-in, or multiple inheritance, language out of Objective-C was the addition of associated references. My earlier post on creating a category that uses associated references is an example of the basic framework to do so. All it was missing was a formal way for the compiler to […]

Steve Jobs RIP

Steve Jobs changed my life. Outside of my immediate family, I think I can only say that about him. I wanted to contribute to his vision. I left graduate school to write Mac software — D2 Software’s MacSpin — to contribute to Jobs’ vision. I followed the siren call of multiprocessor performance and lead a […]

DDGActivity: An Example of Using Associated References

Object oriented languages have always allowed a programmer to add both methods and ivars to any class. Apple recommends you should not over-ride some Cocoa/Cocoa Touch classes. Hence, you cannot use inheritance to add ivars and methods to those classes. Of course, Objective-C has always offered the category mechanism as a way to add arbitrary […]

DDGPreferences: A Class for all Settings

Almost every iOS application has individual user preferences. Some apps also use Apple’s Settings app, some don’t. If you develop many different applications, as I do in my development consulting practice, it is tedious to code up a custom preferences class for each app. My class, DDGPreferences, is an attempt to minimize the tedium by […]

DNS-SD Configuration “Gotcha”

weLost™ uses DNS-SD, DNS Service Discovery, to bootstrap the location of its social network servers. While this was a good idea, it had a very subtle “gotcha” in its configuration. The basic configuration instructions are described here in: Static Server Setup. If you do not intend to support browsing for your resources, then things are […]

Network Reachability

If you write an iPhone application that uses the network, then you must check if the network is both operating and that your server is reachable. Apple has and will continue to reject applications that do not test reachability. To this end, Apple provides iPhone developers a sample application and class, Reachability, that can easily […]

SQLite Persistent Objects

I use Jeff LaMarche’s and his contributor’s SQLite Persistent Objects library in my upcoming iPhone application. This library was created before version 3 of the iPhone OS was released. Because iPhone OS v3 contained Core Data, Jeff and his contributors ceased further development. Yet, I was dependent on it and, hence, I continued private development. […]

The iRush: Programming the iPhone…

’09ers versus the ’49ers: the only differences are the lack of dirt and hookers. The iRush has been underway for 18 or so months now. The facts are clear. This is a great market to experiment with product design and business models. It is also where many small, “long tail” businesses are being formed — […]