In iOS 4, Apple introduced a new way to send “push notifications” to your app without having a dedicated server and associated server side coding. The technique is called as scheduling local notifications. While this tutorial is about how to schedule local notifications, I would also explain how a powerful abstraction concept, Singleton design pattern could make this easier when adding local notification support to your app. If...

Update: An updated version for XCode 4  is available. Please check it out here. I have a habit of creating Singleton pattern classes for nearly every application I write. I manage the Settings Bundle (or any app settings, thru a Singleton class), my MKStoreManager for doing in-app purchases is a Singleton class. Even in Apple’s own code you can see some Singletons like UIApplication, Reachability (from the Reachability example),...

By now, most of you know how to send emails using the Message UI framework without quitting the app. In this tutorial, we will briefly discuss the techniques for sending a HTML formatted email with user generated content. Though sending a HTML formatted email is as easy as setting the option to HTML [picker setMessageBody:emailBody isHTML:YES]; There are some cases that this method that this method doesn’t take care of. In...

Like most of you, I too downloaded the 3.2 beta and was playing around with some iPad stuff. Today when iPhone OS 3.1.3 is released, without second thought, I immediately updated my iPhone. My iPhone being a development device, I understood that I can no longer use the current XCode installation to run apps on device. When I launched XCode, the Organizer reported, “The version of iPhone OS on “ABC’s iPhone” does not match any of...

What is Follow Cost? Follow Cost is a interesting and powerful statistic that helps you check the “cost” you would incur by “following” a person on twitter. This is a very useful statistic that I think every twitter client should adopt.  Tweetie for iPhone was the first to implement follow cost and I use this feature of tweetie to check whether a follower is “worth the pain” (as follow cost puts it). In...