Resources

Android Theory

Android Lifecycles
Room
Coroutines (Kotlin theory)

Backend

Firebase

HTTP Libraries

Retrofit
Moshi

Component Design Helper Libraries

Glide (Images)
Material.io
SDP (For better responseive designs)

Testing

Espresso (UI testing)
Robolectric (Unit Testing)
JUnit (Unit Testing)
Timber (For logging)

Licences

Licenses (Understand the license each library operates under)

Find Libraries

Android Arsenal