Inspiration
I'm thinking on teaching my kids to leverage ai tools to create real product, than i see what kind of app she love. The result is this a virtual companion that feels present throughout the day instead of being limited to a single app screen. Shelby combines the charm of a chibi pet with practical reminders, lightweight conversation, and simple care interactions.
What it does
Shelby Chibi Pet is an Android companion that can appear as an on-screen overlay. Users can feed Shelby, give her water, play with her, let her rest, monitor her needs, chat using scripted conversations, receive reminders and trivia, and customize her appearance and behavior. Progress and memories are stored on the device.
How we built it
We built Shelby as a native Android application using Java, Android foreground services, overlay permissions, Firebase Authentication, Google Play Billing, and a deterministic dialogue engine containing 2,000 original lines.
We utilized Codex throughout development for architecture reviews, debugging, dialogue expansion, UI implementation, asset preparation, automated validation, release tooling, and production-readiness testing.
Challenges we ran into
The most difficult challenges were keeping overlay behavior reliable across Android states, making care actions update consistently, reducing a large animation bundle, organizing a complex Settings experience, and creating scripted conversations that feel varied without relying on an online language model.
We also had to handle authentication, purchase restoration, production feature gating, foreground-service requirements, and Google Play release configuration.
Accomplishments that we're proud of
We created a working animated companion that can live outside the main app, respond to care actions, preserve its state, and provide conversations without requiring an internet connection.
We are also proud of the 2,000-line deterministic dialogue system, the safe memory callbacks, the redesigned Home and Settings experience, and the separation between stable production features and experimental AI functionality.
What we learned
We learned that making a digital companion feel alive depends on many small details: animation consistency, contextual reactions, useful reminders, clear controls, state persistence, and avoiding repetitive dialogue.
We also learned that production Android development requires significantly more than building features. Authentication, billing, privacy, permissions, device compatibility, release signing, accessibility, and Play Console compliance must all work together.
What's next for Shelby Chibi Pet
Next, we plan to improve animation quality, expand customization, add deeper activity and memory systems, and continue refining scripted conversations.
We are also testing an optional account-gated AI conversation mode backed by a secure server, usage quotas, and transparent cost controls. This experimental mode will remain separate from Shelby’s offline scripted experience until it is reliable, safe, and ready for broader testing.
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