Mobilestead Blog

Everyone is raving about the iPhone native apps, and I completely understand why. The biggest thing is the placement in the iTunes AppStore. Once you get there, you have a reach to hundreds of thousands of new consumers. However there are many applications that may just as well designed as a WebApp. Most of the current products are already implemented as a website and it would be a lot easier to publish it as a WebApp. Of course you miss out on the marketing aspect, and all the sexy things that Native apps can do, but you gain with Time to market and development cost. Also your application may not be a genarl availability app, so that further seals the deal.

Native App Web App
Offline Access X
Has local storage Requires Internet Connectivity.
Access to core phone features (GPS, camera, accelerometer phone book, calendar,) X
Updates to new version Requires approval of AppStore (takes a lot of time). Users have to download the updated version Instant since it’s on the server
Portability to other mobile platforms (Android, Blackberry etc) A lot easier
Speed A lot faster
You can define your own caching strategies, your own network services, and your own event/threading model.
Data Storage Persistant data in their own local data store, even being able to use SQLite, and allow offline access.
AppStore Lots of free traffic
Requires approval which can take 2 weeks+
Your application may get rejected
Some of the applications maybe be a B2B product and would not be going to the app store.

Here are 2 good blog posts on the same topic:
I started doing some technical research and have decided that maybe an iPhone WebApp is the way to go vs iPhone (native) App.
It seems that there are some obvious advantages with this:
Right now there are about 3x as many iPhone Apps vs WebApps.
I’ve seen the iPhone Facebook WebApp app vs. Native app and they are pretty close. Facebook has built probably the best WebApp that I have seen. Of course it’s limited: can’t use Facebook Chat, upload pictures etc – but it’s a lot cheaper and quicker to develop.

http://www.appcelerant.com/iphone-app-vs-web-app.html <— A good topic on similar topic
http://keithahern.com/?p=94 talks about wrapping a webapp just to have yourself listed in the AppStore (access to new users)