If you're looking for a specific feature (APQs, Codegen options, @nonnull, ...) the integration-tests have a lot of very focused examples of how to use Apollo Kotlin.
For more general examples demonstrating how to build an App end to end, check:
- https://github.com/apollographql/apollo-kotlin-tutorial for an Android App example
- https://github.com/joreilly/MortyComposeKMM for a Multiplatform App example