How to use build types (debug vs release) to set different styles and app names?

How do I use different resource values for the build types, even if they already exist?

They already exist in the main sourceset. Add other sourcesets for your other build types of interest, where you override the resources you want.

For example, in this sample project I have a main sourceset and a debug sourceset. Both have the app_name string resource in res/values/strings.xml, but with different values. In a debug build, the debug sourceset version of the resource will be used; in any other build (e.g., release), the debug sourceset is ignored entirely, and the main sourceset version of the resource is used.

Note that I do not have a release sourceset. Particularly when overriding resources, this is perfectly fine -- you only need a sourceset for a build type when you want to change something for that build type, not for every build type that you are using.

In File|Project Structure|app|Flavors we have:

Version Name: 1.3

In Strings resource file we have:

<string name="app_name">MyAppTitle</string>

In "onCreate" of MainActivity class:

...//add version to application titleint versionCode = BuildConfig.VERSION_CODE; // unused in my applicationString versionName = BuildConfig.VERSION_NAME;this.setTitle(this.getTitle() + " v"+  versionName);...

The result is "MyAppTitle v1.3"