One urgent problem. Nineteen months. Two app stores.
CowinSlotNotifier was built and operated by BitInfinity during India's COVID-19 vaccination drive, and retired once the problem it addressed had passed.
- Built by
- BitInfinity
- Based in
- Kota, Rajasthan, India
- Operating
- 2021 — 2022
In May 2021 India opened COVID-19 vaccination to every adult. Demand vastly exceeded supply, and slots on the government’s CoWIN platform were taken within seconds of being released. Finding one meant refreshing a page and being lucky.
The Government of India published the CoWIN APIs for third-party use. We used them to build something narrow: an application that let a person describe the slot they needed once — a vaccine, an age group, a dose, a centre or district or PIN code — and then did the watching on their behalf. When availability matched, a push notification went out.
It shipped on Android and iOS from a single Flutter codebase and ran for more than a year. Over that time it was downloaded more than 500,000 times and delivered over 10 million notifications against more than a million standing subscriptions.
By the end of 2022, India’s vaccination programme had progressed to the point where slots were no longer scarce. The problem the app existed to solve had resolved itself, so the service was withdrawn. This site is the record of what it was.
Cowin Slot Notifier
v0.0.3 · Retired
- App Downloads
- 500K+
- Notifications Delivered
- 10M+
- Subscriptions
- 1M+
- App Rating
- 4.5★
Historical figures, recorded across the service’s operating life.
01
Solve one problem properly
The app answered a single question — is there a slot matching what I need — and did not try to become anything else. Everything it shipped served that question.
02
Take only what is needed
Delivering a notification to the right phone needs a device identifier and a push token. So that is all the application ever collected. No accounts, no profiles.
03
Use the public source, and say so
Availability came from the Government of India's published CoWIN APIs. The app never claimed to be official, and pointed people back to CoWIN to book.
04
Stop when the job is done
Once slots were no longer scarce, the reason for the product was gone. Keeping it running would have served us, not the people using it.
The studio
BitInfinity
A software studio based in Kota, Rajasthan, India. CowinSlotNotifier was built and operated here between 2021 and 2022. The studio continues to build; this particular product does not.