As an app developer myself, I can tell you that it makes very good sense to approach the iPhone users first.
That doesn't mean that Android folks will be left out in the cold, but the development platform for Apple is just a good bit more evolved (I'm actually a developer using Microsoft products by day). And the user base is very large for Android, but Apple users are buying and using apps at a much higher percentage.
Also, the iPad as the next step may be very likely. Aside from some slight navigation differences, the only major issue in porting to iPad is the need for some pretty high resolution imagery.
Having downloaded the iPhone app for e90post today, I have to say it's really nice. It gives you Android guys something to look forward too!