IOS vs Android pwa manifest

Because we are using AR.js that uses WebRTC getUserMedia to get access to the device camera we had to do some tricks for the pwa, so ARte can run on both OS. We faced a problem when opening the pwa on 'standalone' mode on IOS devices, we believe that is because safari opens in 'standalone' using WKWebView that doesn't have WebRTC implementations yet. Our workaounr was to create two manifests, one for IOS devices and one for the rest and we also created a script that detect which type of device is accessing the pwa and change the manifest based on this.