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Caelum Review: Free Offline AI Chat App for Android

·6 min read·By Hans Kuepper · Founder of PromptQuorum · Discovery engine for open-weight & open-source AI
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Warning: Caelum has had no update since 14 August 2025 (version 1.3.1), so it may be unmaintained — check that it works on your device before relying on it. Caelum is a free, closed-source Android app that says it runs its AI offline, answers questions about your documents and can optionally search the web through Brave.

Caelum is a free chat and document assistant for Android from Nolan Picard, an independent developer in France. According to its Google Play listing it runs its AI on the phone, needs no account and can optionally search the web through Brave. This review reflects the store listing and an archived copy of the developer's website and privacy policy, as checked on 19 October 2026.

Caelum Review: Free Offline AI Chat App for Android

Key Takeaways

  • Developer: Nolan Picard, an independent developer in France, who published the first release on 10 July 2025 and calls version 1.3.1 the "10th official release".
  • Reach: Google Play shows 10K+ downloads and a 4.1 average from 271 ratings, so the app has a modest public track record.
  • Platform: Android 7.0 or later through Google Play only; no iPhone, desktop or web build was found.
  • Website: the developer's domain no longer resolves, so the product page and privacy policy were read from Internet Archive captures.

📍 In One Sentence

Caelum is a closed-source Android app that, according to its developer, runs an AI assistant on the phone without an account and answers questions about documents you import.

💬 In Plain Terms

You install it from Google Play and chat with it; imported documents are read on the phone, and web search is a separate optional feature that sends only your query to Brave. The developer does not name the model it uses.

📌Note: This review is based on the Google Play listing, an archived copy of the developer's website and privacy policy, and the developer's public GitHub profile, checked on 19 October 2026. This review itself involved no hands-on use or benchmarking; a separate first-hand test is linked below.

What Is Caelum?

Caelum is an Android chat assistant that, according to its Google Play listing, runs "advanced on-device AI" instead of calling a cloud service. The listing describes three parts: a private chat, a document reader in which you import files and ask questions about them, and an optional web search through Brave whose results are temporary. The listing is titled "Caelum - Local AI assistant"; the developer's site called it "Caelum - Local AI for Android".

The listing names its developer as Nolan Picard, based in France; the app is published only on Google Play.

Get It

Caelum is installed from Google Play like any other Android app; no sideloading, terminal or account is involved. The developer's website, which the listing links, no longer resolves, so the privacy policy is linked below as an archived copy.

Platform
Where to get it
AndroidGoogle Play (free install, Android 7.0 or later)
Websitecaelum-app.me (no DNS record on 19 October 2026; archived copy from 10 May 2026 available)
Privacy policyArchived copy (captured 10 May 2026; policy text dated June 2025)

Version reviewed: 1.3.1, shown on Google Play as last updated on 14 August 2025; the listing gives 10 July 2025 as the first release. The 1.3.1 notes list better web search, support for images with text and PDFs, better document handling, message deletion, bug fixes and Ukrainian language support.

Features Confirmed by the Sources

Every item below comes from the Google Play description, the 1.3.1 release notes or the archived website.

  • Chat. Natural conversation with the on-device AI, light and dark themes, a layout that adapts to tablets and, since 1.3.1, deletion of individual messages.
  • Document reader. You import documents, ask questions and get answers; the listing says the files are processed on the phone. The 1.3.1 notes add support for images that contain text and for PDFs.
  • Optional web search. Searches current information through Brave Search; the listing says results are temporary and no history is stored.
  • Languages. Version 1.3.1 added Ukrainian; the sources do not list the other languages the interface or the AI supports.

Privacy and Network Use

According to the privacy policy, conversations stay on the device, documents are processed locally and not transmitted, and no account is created. The policy lists what is not collected: name, email, phone number, location, a unique device identifier, advertising-tracking data, browsing history, financial and health data. It also says there is no central server and that external traffic uses HTTPS.

The one declared outflow is the optional web search, which sends your search query to Brave Search. The Google Play Data safety section says "No data collected" and also that the app may share app activity with third parties, which matches the policy's own wording that search history in the app is collected and shared with Brave. Declared permissions include network access, keeping the device awake, reading and writing shared storage, Wi-Fi state, downloading files without notification and the Google Play licence check.

📌Note: The app is closed source, so none of these claims can be checked in code, and PromptQuorum has not audited network traffic. Anyone handling confidential documents should verify behavior on their own device first.

Who Should Use It

  • Android users who want a free chat and document app without an account. Install is free and needs no sign-up.
  • Readers comparing offline Android chat apps. The sources show what this one claims.

What We Could Not Verify

  • Hands-on performance. This review itself does not assess speed, battery use or answer quality. The separate hands-on test (one phone, one session) covers the first run, photo input, web search and a logic prompt, but did not time answers or test offline use.
  • The model. The listing says "advanced on-device AI" and the sources name no model, size, source or runtime, so it is unknown what the app actually runs.
  • Offline behavior. Whether the AI is bundled or downloaded on first run, and whether the app works in airplane mode, is untested; the listing says no internet is needed after installation.
  • Hardware needs. No RAM or storage requirement is stated; the only stated floor is Android 7.0.
  • License and source code. The app is closed source; the developer's public GitHub profile holds no Caelum repository.
  • In-app purchases. The install is free and the description names no purchases, yet the listing's content-rating labels mention in-app purchases.

Competitors and Alternatives

MemoryAI

Platforms:
iOS, Android
Price / license:
Free / closed source
Key difference:
Closed-source offline chat with document Q&A, editable memory and voice
Articles about MemoryAI (1)

Competitor details change often; confirm each app's current price, license and platforms on its own listing.

Compare in directory

Frequently Asked Questions

Is Caelum the same as "React Native AI"?

The Google Play package is com.reactnativeai, but the product is called Caelum, and none of the sources describe it as anything other than the Caelum app.

Does Caelum work on iPhone or desktop?

No such build was found. The archived website called it local AI for Android and linked only Google Play.

Can I still reach the developer?

The domain caelum-app.me returned no DNS record on 19 October 2026 when checked with two public resolvers. The Google Play listing still shows a developer page and a support email address.

Verdict

Caelum is a free Android chat and document app with a clear privacy pitch and no account, but that pitch is untested and the project appears unmaintained: it is closed source, names no model and has a website that no longer resolves. The missing updates described in the warning at the top weigh most. It suits readers who want to try a free assistant and accept those risks; anyone who needs a maintained app should compare Private Mind or PocketPal AI.

Sources

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