Android uses a Java-based language. Eclipse is the common IDE used through the ADT Plugin, which fully supports Android development. Though Eclipse is commonly used, it is still a difficult system for some to learn. The same goes for XML (which adds another layer of complexity when working with the UI), especially if you are used to CSS for design. The NetBeans IDE is another supporting platform that can also be used via a plugin. Developers can use any text editor to edit Java and XML files, which they can pair with command line tools to develop and debug Android apps and control Android devices.
Android has a 70.1% market share (as of the end of 2012), creating a higher demand for the apps. The number of tools at the developer's disposal and the availability of forums and other online support systems prove that Android is geared more toward developers being able to create at will. The downside to this freedom is that the quality varies depending on the app, and the developer has very little to hold him/her accountable to any expectations besides that of the customer.
The Android SDK is an amalgamation of different tools that allows anyone interested to develop and manage their applications. Some of those tools include:
Tools like The Simple Project and RFO BASIC! provide needed support and training for novices.
One of the biggest benefits to developing apps for Apple is the ease of Xcode. Get a MacBook and install it, and suddenly you can begin writing and installing apps. Android isn't that simple.
One of the main differences in developing apps for Apple is interface construction. When working with a fragmented ecosystem such as Android, you have to take into account all the various types of devices that run Android; with iOS, there are only two resolution scales to take into consideration.
Outside of the comparison between these two systems is HTML5, which allows developers to write apps that are more efficient and faster than Flash apps of yesteryear. HTML5 apps have a lot of benefits over native apps, but they should be used with caution for the time being due to their lack of web standards and missing libraries.
Both systems provide tools for development and distribution. Both have markets that are central to whatever the developer would like to provide in the way of applications. Both languages are being adjusted for cross-development platforms.
In conclusion, while Android offers more opportunity, Apple may offer better checks, which assure quality and distribution. Basically, a developer needs to consider which option best suits the application they intend to create and not worry about answering the flawed question of which mobile OS is better.