No worry, here come SBQR, an alternative solution build upon CanvasCamera and jsQR.
A few notes though :
- While it should be compatible with iOS, I have no device to test it.
- It won't work on Android KitKat, you'll need Android 5 or above.
- As far as performance goes, I did my best, used web worker to separate the workload in two threads, but it's still JS. It will slow down on older devices.
- I'm the biggest JS noob, so if you have any correction, I'll take them gladly!
- Last but not least : to compile with it, you have to have GIT on your computer and set it up in PATH in your environment variables.