Cannonball for Android

Cannonball is the fun way to create and share stories and poems on your phone. Start with a beautiful image from the gallery, then choose words about #adventure, #romance, #nature or #mystery to complete the story and share it with friends.


This repository contains the source code for Cannonball, an Android application written in Java built with Firebase.

Cannonball is a canonical sample Android app to demonstrate how to use Firebase, the easiest way to build the best apps.

Cannonball uses many of the features available in Firebase, including Realtime Database, Crashlytics, Google Analytics for Firebase, and Firebase Auth.


Cannonball flow


If you've found an error in this sample, please file an issue.

Patches are encouraged, and may be submitted by forking this project and submitting a pull request through GitHub.


This project uses Gradle 4.4

To get started and run the app, you need to follow these simple steps:

  1. Clone this repo via command line (git clone or Android Studio
  2. Run "Sync Project with Gradle Files" via command line or Android Studio
  3. If you don't already have a Firebase account, sign up for Firebase at
  4. Follow the instructions to add Firebase to your Android app
  5. Enable Phone Sign-In and Anonymous Sign-In


Cannonball for Android is compatible with Android SDK version 17+.