Nit a matter of which is easier its a matter realky of language, there written in different programming languages if you have no programming experience at all then it will take alot more effort for you to learn a language, i believe androids writting in java and ios in c
Do you have any programming experience? If yes, do you know OOP/MVC? That is the big challenge. If you're close to that level then you need to pick a platform. Java works on tons of different systems but is an absolutely horrible programming language. Objective C is little easier because it does many things automatically. Then you need to learn Cocoa and whatever else you need specific to your app.
It is not a trivial thing. You can also use one of the prebuilt platforms like Gamesalad, etc to do stuff without understanding the underlying code.
No programming experience. I am looking to tie in an ap to gps function for reference for travelers. I wish I could just sell the idea to someone. Guess I am going to have to look somewhere else for extra money.
Learning anything new has a learning curve....but if you are asking I assume you are ready to learn. Use a tutorial....try easyappcreation.com to learn how to build and sell your app.