Aerzeit
Press Kit
Aerzeit is a privacy-first iOS app for Stoßlüften — German short-burst window ventilation. Pick a target indoor temperature; the app tells you when outside-air conditions match, twice a day. Structural privacy: an empty iOS Privacy Manifest (no required-reason APIs called) and a v1-never-breaks commitment (we never remove or break what you rely on — your notifications and privacy are guaranteed for the life of v1; improvements are additive, funded by the small annual subscription); the backend sees only an H3 grid cell, no identifiers. No ads, no tracking, no data sale. Built and published independently by Samuel Harrold (Indianapolis, Indiana, USA).
Shorter version, if you need it: Privacy-first iOS window-ventilation timer that tells you when outside air matches your target indoor temperature.
The Stoßlüften story
Aerzeit takes its name from Stoßlüften — the German habit of brief, timed bursts of window-opening instead of leaving a window cracked all day. The name reflects that idea directly: a coined compound of the Greek aer (air) and the German Zeit (time). Aerzeit automates the timing of that habit — comparing the local outdoor forecast against a target indoor temperature you choose, and notifying you morning and evening when it's the right moment to open up.
Fact sheet
- Platforms
- iPhone and iPad, iOS 16.4 or later
- Price
- $9.99/year (App Store subscription; regional pricing applies)
- Availability
- App Store
- Privacy
- Empty iOS Privacy Manifest (
NSPrivacyAccessedAPITypes: []) — no required-reason APIs called. No accounts. No analytics or tracking SDKs. No third-party SDKs, with one exception: an open-source geospatial-math library with no system-API access. The backend learns only an H3 grid-cell ID (~3 km resolution) per forecast request — never raw GPS, a name, or an account identifier. - Server region
- EU (Cloudflare Workers, Western Europe)
- Publisher
- Samuel Harrold, Indianapolis, Indiana, USA — an independent project, not affiliated with any consulting business.
Screenshots
Aerzeit's interface uses a single dark theme (no separate light-mode variant). These are the current App Store screenshots (English (U.K.) localization):
A few additional screenshots (chart tooltip, precipitation filter, expanded privacy detail) are available on request.
App icon
1024 × 1024 PNG · 512 × 512 PNG
Contact
Press and editorial inquiries: support@aerzeit.app — every message is read.