I also don't have a preference between Java and Objective-C.
iOS costs money each year to develop for, requires a Mac to program on, requires your app to submit to approval for every update, and is extremely locked down and terrible.
I think I've made it clear what my answer is.
What kind of app are you planning on making? Free or paid? Game or utility?
My advice is to go through introduction tutorials for both. You can download the developer tools for iOS or Android for free. You can test your apps on a physical Android device for free; but for iOS, you're stuck with the simulator unless you plop down $99.
Do you want to do this as a hobby? for me?
If a hobby, I'd lean towards Android, because it's more open and easy to deal with. I can interface with Arduinos or practically anything else without having to deal with licensing fees. I have more freedom to roam API-wise.
If for money, iOS hands down. Android may have bigger market share, but the money is still in the iOS App Store. More people buy apps for iOS, sad but true.
To distribute on Google Play is a one off fee of $25. To be an official Apple Developer is $99 a year.
You can of course just develop apps for jailbroken iOS devices, that won't cost you anything and you can do it on Windows; but if you want to do it professionally then you need to become an official dev.