This is a personal project of mine and not intended for general / wide-spread use.
MyTicket is a prove of concept to show how you can build a simple web app that displays a QR code that could be used as a ticket for transportation. This would be a simple solution to have your QR code on an additional device as a backup in case the primary device might run out of battery.
When you visit the web app you find a simple page inspired by the designs of common e-ticket apps. The page includes some editable text fields for detailed information and a central canvas where a QR code can be displayed. To change the fields one can tap on them and enter custom information. The QR code chessboard placeholder can be replaced by a QR code image that will be parsed into an array of black and white squares.
This project is a Progressive Web App, which means that you can install it for offline usage via your browsers menu under "add to homescreen".
The app is served as static webpage that requires no server-side processing. All data is stored in LocalStorage on the client device.
I have my personal instance running under https://myticket-app.z3ro.one