Write applications in C or C++ for Android?

For anyone coming to this via Google, note that starting from SDK 1.6 Android now has an official native SDK.

You can download the Android NDK (Native Development Kit) from here: https://developer.android.com/ndk/downloads/index.html

Also there is an blog post about the NDK:
http://android-developers.blogspot.com/2009/06/introducing-android-15-ndk-release-1.html

The Android NDK is a toolset that lets you implement parts of your app in native code, using languages such as C and C++. For certain types of apps, this can help you reuse code libraries written in those languages.

For more info on how to get started with native development, follow this link.

Sample applications can be found here.

Normally, you have to:

1. Install Google Android NDK. It contains libs, headers, makfile examples and gcc toolchain
2. Build an executable from your C code for ARM, optimize and link it with provided libs if required
3. Connect to a phone using provided adb interface and test your executable

If you are looking to sell an app:

1. Build a library from your C code
2. Create simple Java code which will use this library
3. Embed this library into application package file
4. Test your app
5. Sell it or distribute it for free