Legal

Privacy Policy

Effective October 27, 2026 · Last updated October 27, 2026

The short version: Spare Tank has no ads, no analytics and no tracking, and we don't sell or share your data. You don't create an account with us. Your messages go only to the host and AI models you choose to connect. Chat history and settings stay on your device unless you send them to a host or model you control or choose.

This policy explains how the Spare Tank app for iPhone, iPad and Mac (the "App") and the website at sparetank.app (the "Site") handle information. Spare Tank is made by Arcem LLC, Needham, Massachusetts ("we", "us").

1. Information we collect

We do not collect personal information through the App. We don't operate an account system, and the App contains no advertising, analytics, crash-reporting or tracking software. It does not use your data to track you across other companies' apps or websites.

2. What stays on your device

Settings, such as the address of the host you pair with, the Ollama addresses you add and your model choices, are stored in the App's local storage on your device.
Local chat history (conversations with Ollama models) is saved in the App's private storage on your device, limited to the most recent 300 messages, along with any unsent drafts.
Deleting the App removes this data from that device.

3. Where your messages go

The App sends what you write or dictate only to the destinations you set up:

Your host. The App pairs with a host address you enter, typically a small service running on your own Mac and reached over a private network such as Tailscale. Conversations and task records sent there are stored on that host, under your control, not by us.
AI providers you choose. Your host passes messages to the AI services you've signed into (for example, through a provider's official app or command-line tool). Each provider handles your messages under its own terms and privacy policy. The App itself stores no provider passwords or API keys.
Ollama servers you add. Local chat sends messages directly to the Ollama addresses you configure, such as your Mac or another computer you run.

When one model reaches a usage limit and Spare Tank switches to another, the recent conversation is sent to the next model you've chosen so it can continue. We don't receive a copy of your messages along the way.

4. Microphone and speech recognition

If you choose to dictate, the App asks for microphone and speech-recognition permission. Speech is converted to text using Apple's on-device recognition only; the App does not fall back to a cloud service. Audio is not recorded or stored. Only the resulting text is used, like anything you type.

5. Local network access

The App may ask for permission to find devices on your local network. It uses this only to reach the host and Ollama servers you configure.

6. The website

The Site uses no cookies, analytics or advertising. It is hosted on Cloudflare, which processes basic technical data such as IP addresses to deliver pages and protect against abuse, under Cloudflare's privacy policy. If you email us, we use your message and address only to reply.

7. Sharing and sale

We don't sell, rent or share personal information, and we don't use it for advertising. Because we don't collect it, there is nothing for us to share.

8. Children

Spare Tank is not directed to children under 13, and we do not knowingly collect information from them.

9. Your choices

You decide which hosts, providers and models the App connects to, and you can change or remove them in Settings at any time. You can revoke microphone, speech-recognition and local-network permissions in your device's Settings. Data held by a host you run or a provider you use is managed there.

10. Changes

If the App's data practices change, we will update this policy and the date above before the change takes effect.

11. Contact

Questions about privacy: keith@arcemdigitalsolutions.com, Arcem LLC, Needham, Massachusetts, USA.