Hi,
I was testing Nextcloud Talk video and chat using Android Chrome browser on the mobile device, and it seems to work well.
So just to confirm, android and iOS phones can simply use their mobile browser to access video conferencing Talk, and no need to download a dedicated app?
Yes, and it works 
App has a few more features e.g. ringtone options etc.
Also it would be nice if it can also remote control (which is impossible unless install something on client computer), and also would be nice if it has a whiteboard tool to draw something over the remote screen sharing