What programming languages are used in making Smartphone apps?

That depends on which platform. I will have to dig a bit more for specific numbers, but I can tell you that Apple makes it harder than Android, if for no reason other than the cost of the development tools, the cost of the developer’s license, and the hefty chunk they take out of the sales revenue.

Actually, it will have to wait… it’s 2AM here and I am too tired to look it up right now.

My knowledge is based on iPhone development. iPhone software is written in Objective-C and makes heavy use of Apple’s very extensive Cocoa Touch Frameworks. Pricing is going to greatly depend on the functionality you need/want, as well as the design resources you’re willing to invest. You could probably get someone to make you a flashlight app (i.e. turns your screen white) for very little money, but things quickly get into the tens of thousands of dollars for something non-trivial. To do something very complex you could be looking at much more than that.

@jerv the tools are free with a Mac, and it’s free to develop free apps (I think), and it’s only $100/year for an account to be able to sell apps. You’re right about the 30% commission though, but to be perfectly fair, most developers are going to be paying some payment-processing and support costs related to software distribution anyways. 30% is a pretty good deal for very cheap apps, and fairly hefty for expensive apps.

Each of the major vendors has decided on their own approach.

Androids usually are written in Java.

Nokia uses a strange one called OPL (Open Programming Language)

Microsoft Windows Mobile uses scripting and C# or visual C++

So it depends…

iOS usually uses Obj-C, though it is compatible with basically anything. You have to pay a symbolic fee of 70€ to register as a developer and to test and compile you need a Mac (or a computer running Mac OS, at least).

Android is open source, so you can use pretty much anything on it and as long as you compile it properly it’s not a problem what you use, though there is the issue of performance compliance. I.E. you can compile unreal tournament 3 on android, but there is no way in hell that’s gonna run on any level.

Basically what you need is to download the testing platform and the framework to work under, then it depends on what you’re trying to do.

@jerv :: xCode will work on a hack. I use it. They are bit of a pain in the ass unless you buy the right hardware. Mine pretty much worked out of the box.

The easiest route could be javascript+html+css, especially with platforms like phonegap (free) or titanium.