1. At a glance
- The app has no account or login.
- Calculator inputs and results, jobs, customer fields, notes and PDF contents stay on your device.
- Pairmind receives pseudonymous product analytics and purchase records so we can improve the app and unlock Pro.
- We do not sell app data, use it for targeted advertising or track you across other companies' apps or websites.
2. Who controls the data
Pairmind Limited is the data controller for the information described in this policy.
Pairmind Limited
7/F, MW Tower, 111 Bonham Strand
Sheung Wan, Hong Kong
hello@pairmind.dev
3. Data kept on your device
HVAC Calculator & Ductulator stores the content you create locally: calculator inputs and results, saved jobs, customer names and addresses, notes, settings and generated PDF reports. Pairmind does not receive this content. When you share a PDF, iOS sends it to the destination you choose; the app does not send Pairmind a copy.
4. Data we collect
| Category | Examples | Purpose |
|---|---|---|
| Purchase History | App Store product, transaction, trial and entitlement status | Validate and restore Pro, measure purchase outcomes |
| Device ID | Random app or install-scoped identifiers | Measure use and connect purchase events |
| Product Interaction | Screens and calculator types used, paywall actions, purchase status and PDF export | Understand feature use and improve the app |
| Other Usage Data | App install, open and background events | Understand app use and reliability |
Analytics may include technical context such as app and build version, device model, iOS version, locale and time zone. A network request also reveals an IP address to the service receiving it. These categories are not linked to your name, email, Apple Account or another real-world identity, and they are not used for tracking.
5. Product analytics
We use PostHog as a processor to understand which parts of HVAC Calculator & Ductulator are useful. Events never contain your inputs or results: they record only which calculator was used, paywall actions, purchase status and PDF export. Events use a random pseudonymous identifier, which HVAC Calculator & Ductulator also passes to RevenueCat so purchase events and analytics can be joined without a name, email or login. Session replay and element autocapture are disabled. Read PostHog's privacy notice.
6. Purchases
Apple processes payments made through the App Store. Pairmind does not receive your card or bank details.
We use RevenueCat as a processor to manage Pro. RevenueCat receives a random app-scoped customer identifier, App Store transaction data, product, trial and entitlement status, the random analytics identifier described above and, if you arrived from an Apple Search Ads campaign, Apple's AdServices attribution token, which tells us which campaign led to the install without identifying you. Pro is sold as a one-time lifetime purchase; earlier versions also offered monthly and yearly auto-renewable subscriptions. Read RevenueCat's privacy notice and Apple's privacy policy.
7. What we do not collect
- No account profile, name, email address or phone number through the app.
- No calculator inputs, results, job or customer text, notes or PDF content.
- No location, contacts, photos, camera or microphone access.
- No payment card or bank information.
- No advertising identifier (IDFA).
- No session replay or screen recording.
8. Sharing and international transfers
We do not sell personal information. We share the limited data described above only with PostHog (analytics), RevenueCat (purchase validation) and Apple (App Store and payments). Pairmind is based in Hong Kong; these providers may process data in other countries under their own safeguards. We may disclose information if required by law.
9. Retention and deletion
On-device data remains until you clear history in HVAC Calculator & Ductulator or delete the app. Analytics events are kept only while needed to improve HVAC Calculator & Ductulator, then deleted or aggregated. Purchase records are kept while needed to validate and restore Pro and to meet legal duties. To request deletion, email hello@pairmind.dev.
10. Legal bases
Where required, we process purchase data to provide the Pro features you requested, and limited analytics for our legitimate interests in operating and improving HVAC Calculator & Ductulator.
11. Your choices and rights
Depending on where you live, you may have rights to access, correct, delete or receive a copy of personal information, and to object to or restrict processing. Email hello@pairmind.dev. You may also complain to your local data-protection authority.
12. Children's privacy
HVAC Calculator & Ductulator is not directed to children under 16. We do not knowingly collect personal information from children.
13. Security
We use reasonable safeguards, including encrypted network connections. No method is completely secure.
14. Changes to this policy
We may update this policy when HVAC Calculator & Ductulator, its providers or legal requirements change, and will change the date at the top.
15. Contact
Email hello@pairmind.dev or write to Pairmind Limited, 7/F, MW Tower, 111 Bonham Strand, Sheung Wan, Hong Kong.