Sky Map

http://stardroid.app

Sky Map is the open-source astronomy Android app built for the community.

Need Help?

Check out help.md and troubleshooting.md for accuracy issues and why 'compass calibration' doesn't do what you think it does.

FAQ

Is this Google Sky Map?

It was originally!

Sky Map has a long history, launching as Google Sky Map on the very first Android phone at Searchology 2009. In 2011 Google ceased active support and the original developers open-sourced it with Google's permission. Google's Open Source Programs Office kindly allowed us to continue to work on it as a personal project, provided we removed Google's branding from it and did not use Google's resources. Today it is still maintained by the same folks. While we no longer work for Google we continue to develop Sky Map using our own resources.

Then what is stardroid?

"Stardroid" was the internal name - you can see it's still used as an identifier in the code. Back in the day Google's lawyercats were concerned that 'stardroid' might attract the wrath of, let's say, followers of the Dark Side of the Force so we were strongly encouraged not to call it that. Plus, Google likes to name products after what they are (Photos, Calendar, Docs...). So, Sky Map it is.

Why does it lack feature X or look so dated?

Check out Sky Map v2! It's a complete rewrite and not only does it look more like a modern Android app but it's a solid platform to build new features on. Expect more features very soon!

If you're still on v1 though, Android has evolved significantly since 2009. While most of the code has been rewritten since its Google days, the architecture reflects its origins which is why it looks somewhat retro. Nevertheless, we are continually inspired by the community of users who still find joy in its simplicity and quirks.

How can we help?

I'm glad you asked! We have a section on that below.

---

Support the Project

Sky Map is a labor of love maintained in our spare time by a couple of ex-Googlers here in Pittsburgh. It is free, open-source, ad-free and we don't track you or sell your data.

If you enjoy using Sky Map, there are several ways to help keep the project alive:

• Donations: Buy Me a Coffee — Every coffee helps keep the servers running and the code flowing!
• Join the beta and give us feedback! Visit the Play Store on your phone.
• Star the Repo: It costs nothing and helps others find the project.
• Contribute: See the Contributing guide or report an issue.

Find us elsewhere

• Facebook @stardroidapp
• X @skymapdevs

---

Contributing

IMPORTANT: Contributions are currently closed! The V1 codebase has been retired and any contributions would be wasted. Watch out for ways to contribute in V2 once it's a little more settled.

Bug fixes, dependency upgrades, and translations are always welcome. For major changes or new features, please email us first — we may have a different vision and it would be a shame for your work to go to waste.

See CONTRIBUTING.md for full details on build instructions, coding style, and how to submit a PR.

---

Licensing, Ownership & Trademarks

Sigh. I'm sorry we have to do this. But this legalese is to prevent lazy people taking the source code and releasing a clone of Sky Map that is just stuffed full of ads. Yes people do this. It adds no value to the world and just lines their pockets.

1. Source Code License

The source code of this project is a derivative work of the original open-source Sky Map application (formerly Google Sky Map). The repository holds two applications:

• stardroid-v1/ — the legacy app. Licensed under the Apache License, Version 2.0. Original copyright headers and notices within inherited files have been preserved as required by the Apache 2.0 terms.
• stardroid-v2/ — the current rewrite, authored by Penterakt LLC. Licensed under the GNU General Public License v3.0 (GPLv3), with an additional permission under GPLv3 §7 for distribution through app stores. See stardroid-v2/LICENSE.md for the full terms and stardroid-v2/NOTICE.md for its own Apache-2.0 provenance.
• Combined Work: The project as a combined distribution is compiled and distributed under the terms of the GPLv3. Any third-party forks, modifications, or derivative versions of this combined codebase must be completely open-sourced under the GPLv3.

2. Branding & Visual Assets (All Rights Reserved)

The open-source code licenses (GPLv3 and Apache 2.0) apply to the functional source code, resources, and translations. A short, explicitly enumerated list of brand identity assets — launcher and notification icons, onboarding artwork, and similar identity marks — is reserved as Copyright © 2026 Penterakt LLC, All Rights Reserved. For stardroid-v2/, the authoritative list is the [arr] section of stardroid-v2/ASSET-LICENSES.txt; nothing else in that module is reserved.

Reserved brand assets are NOT open-source and may not be used, duplicated, or modified in any third-party fork or distribution without express written consent from Penterakt LLC.

(Note: This reservation excludes any public-domain or open-licensed scientific datasets, such as NASA/ESA astronomical imagery or public star catalogs, which remain governed by their original respective terms.)

3. Trademark Notice

The app name, project titles, logos, and associated branding elements constitute protected trade names and trademarks of Penterakt LLC.

Subject to the platform terms of the public code hosting service (e.g., GitHub's permission to view and fork repositories on-platform for personal use), you are strictly prohibited from using these trademarks or protected app names in any independent fork, clone, or marketplace distribution. Any independent compilation or distribution of this application published to any app store (such as Google Play, F-Droid, or Amazon Appstore) must be entirely re-branded under a unique identity.

---

Fun

Sky Map Prototype (2009)