Create Free/Paid versions of Application from same code

Question

So I\'m coming down to release-time for my application. We plan on releasing two versions, a free ad-based play-to-unlock version, and a paid fully unlocked version. I have

Answer 1

Gradle allows to use generated BuildConfig.java to pass some data to code.

productFlavors {
    paid {
        packageName "com.simple.paid"
        buildConfigField 'boolean', 'PAID', 'true'
        buildConfigField "int", "THING_ONE", "1"
    }
    free {
        packageName "com.simple.free"
        buildConfigField 'boolean', 'PAID', 'false'
        buildConfigField "int", "THING_ONE", "0"
    }