An android app makes waay more sense
In terms of smartphone market share, at the end of August 2012 Android's was 50.8% while Apple's Iphone was 31.4%.
That being said, why have an iphone app, if you have to choose one; and, if you are going to have an iphone app, why not have an Android phone?
Why not support the majority of your users who use smartphones?
For two reasons:
It is significantly easier to develop for iPhone: there are only two screen sizes and a handfull of devices. Developing for Android is harder due to the wide range of possible devices and form factors.
The data about total market share is very misleading, and not the number that actually matters. While it's true there are more Android devices, it turns out that there is more app and Web usage coming from iOS. This is partly because many of the Android devices out there are lower end phones that are not fully capable of browsing, and usually don't come with very robust data plans.
That said, we will have an Android app. We just had to prioritize.
No problem; I remain optimistic.
As an android developer, the claim that android is severely fragmented is not really accurate. Here is an article that reflect my experience: http://www.localytics.com/blog/2012/android-not-as-fragmented-as-many-think/
I remain optimistic.