Apps vs. the Web

http://www.alistapart.com/articles/apps-vs-the-web/

• Speed: JavaScript performance has increased dramatically in the past few years, but as an interpreted language, it will never be as fast as compiled code that runs directly on the processor. In a mobile environment where processors run slower to conserve power, every clock cycle counts.
• Data Management: Cocoa Touch has several mechanisms that make it easy to store your application’s data. This is important because caching information retrieved from a network can greatly improve a mobile application’s ease of use. The persistent data storage in HTML5 provides simple key/value access or raw database access using SQL. Core Data on the iPhone provides a much more sophisticated system where relationships between your data objects are managed automatically.
• Animation: One of the hallmarks of both web and native iPhone applications is animation that reinforces a user’s actions. CSS3 provides ways to animate page elements, but much more sophisticated effects are possible when you access the underlying Core Animation framework with native code.
• Resources: Mobile developers never have enough memory, network speed, or CPU power. These limited resources are much harder to control when they’re being managed by JavaScript or the browser. It’s easier for native applications to detect these situations and adapt the user experience accordingly.
• Usability: iPhone users feel most comfortable when they’re using the standard controls they’ve become accustomed to in Apple’s built-in apps. HTML abstracts controls like <input> and <textarea> so they can work in many different environments. JavaScript frameworks, like jQTouch mentioned above, do a fantastic job extending these basic control mechanisms, but an iPhone user will still notice that they feel a bit different than platform-native controls.
• Productivity: From the developer’s point of view, it’s typically easier to build complex user interfaces using Cocoa Touch: The frameworks do much of the heavy lifting and allow you to focus on the problem rather than its implementation. With the limited amount of screen real estate on a mobile device, a simple form on the desktop often turns into multiple views whose state needs to be managed by your application. Apple developed Cocoa Touch specifically to deal with this situation.
• Integration: An iPhone has many capabilities that are beyond the reach of the web browser. Some simple examples are the user’s contacts, the photo library, voice recording, and device movement. Cocoa Touch frameworks are the only way to access this information.