1) I find no way one that can contact the developer(2).
2) I have a profile that should be silent and yet which just now result in a sound when an WhatsApp message arrived. I need somewhere to send a screenshot of my profile too - somewhere to give a proper bug report.
3) When I loade this ‘nolt.io’ page on my phone (using Firefox), I saw a lot of grey text on a white background - and the grey text was so faint that it was unreadable. (I type now on a PC.)