Yes, one of the more popular features they offer is their in-depth analytics. This allows you to see things like open rate and click-through rates. It also makes it easy to take action on your stats. For example, you can easily resend a newsletter to anyone who didn’t open the first email or create a segment based on people who clicked a specific link.
If Objective-C isn't your thing, their is Titanium from Appcelerator, you use JavaScript to build your app and it gets compiled into Objective-C. Mobile Tuts has a nice tutorial on how to consume the Twitter API, which is also REST based. It should give you a good foundation to get you started. (
After you have entered your "List Name" you will need to enter a "List Description." Here is where you will describe the kind of information you'll be sending from this list. There is a 400 character limit for the "List Description." Subscribers will see your "List Description" on the unsubscribe page if they ever go to unsubscribe from your list. Once you are done entering your "List Description" click the "Next Step" button.