Building an app on public data
Live apps from public data.
The app reads the public source and keeps the page current at its own address. When a source needs a key, the app's server code holds it.
We built a live departures board for London's Underground this way. It runs at tubetimes.instroc.app.
Five live boards worth making
The bus stop
A board for my bus stop with the next three buses and how many minutes away each one is.
Server code that reads the source · Refresh on a timer · An instroc.app address
- Server code that reads the source
- Refresh on a timer
- An instroc.app address
Every plan, Free included
The air quality
A page that shows today's air quality in my city and keeps a chart of the last 30 days.
Scheduled jobs · Its own database · Charts from saved readings
- Scheduled jobs
- Its own database
- Charts from saved readings
Every plan, Free included
The bike docks
A board of every public bike dock near my office with free bikes and free spaces.
Refresh on a timer · Its own database · Visitor analytics
- Refresh on a timer
- Its own database
- Visitor analytics
Every plan, Free included
The league table
A results page for my local league that saves each week's table and shows who moved up.
Scheduled jobs · Its own database · History you can query
- Scheduled jobs
- Its own database
- History you can query
Every plan, Free included
The river watch
A river level watch for my town that sends a notification to everyone who asked for one when the water rises.
Scheduled jobs · Browser notifications, one switch · Its own database
- Scheduled jobs
- Browser notifications, one switch
- Its own database
Every plan, Free included
Asked before starting
- What does a live data app cost?
- You can build and publish one on Free. A board that refreshes often counts requests against the app's Cloud allowance. Free is $0 with 30 credits a month (5 messages a day). Hobby is $6 a month, Starter $15, Pro $40 and Business $80. Running a published app draws on Instroc Cloud: Free comes with $5 once. Paid plans renew every month: Hobby $5, Starter $10, Pro $20 and Business $25.
- Do I need a key for the data?
- Many public sources need none. When one does, you add it to the app's settings and the server code uses it, so it never reaches the browser.
- Can it keep history?
- Yes. A scheduled job can save each reading to the app's own database, and the page can chart the last day, week or month.
- Which data can I use?
- Any source you are allowed to use that answers over the web. Check the source's terms, and say which source you want in your sentence.
- Can I take the code with me?
- Yes, on every plan. The app is real React and TypeScript, and you can view and download the source whenever you want. Paid plans add a code editor in the browser.
Send the sentence. Change any word first.
After sign-up the sentence is waiting in your prompt box. Nothing is built until you press send. The Free plan needs no card.