by Jay Dee
This is really a proof of concept which will allow you to use different ringtones for dual SIM phones that only support one (eg Android 5.1). First disable your existing ringtones and then re pick them in the sound play blocks within this flow. They will be played through the ringer channel so that your phone's ringer volume still applies. The sounds are played in separate fibres which are killed when you answer the phone or the caller hangs up. You can modify this to let you use a file picker and select your own ringtones or to have a custom ringtone for different callers.
on the check expression block you will probably need to use the number 1 instead of 3 - unless you've changed Sims in the past (Android remembers them and increases your subid each time hence I've got it set to 3)