The suggested solution is a podto: scheme. The scheme is the http: part of a url; the email scheme is mailto: for example. Tapping scheme links usually makes the OS open whatever app is registered with that scheme and sends the text that comes after the colon to that app.
In the last episode of 2017, Oisin’s iPhone X is stolen by Mexican police, we discuss apps using black backgrounds on the X’s OLED screen for dark modes, the launch of Castro 2.6’s backup / restore feature (including a daring live performance of Padraig restoring his main device) and the new App Store pre-orders feature.