Works on Opera, Firefox and Chrome. 'Should work' on android and IE but not checked.
library used: https://github.com/mattdiamond/Recorderjs
In browser recording is not supported on Safari. but maybe if you use flash instead of html it could work such as this library https://code.google.com/archive/p/wami-recorder/
this seems like the best option for flash https://code.google.com/archive/p/wami-recorder/
Deets for uploading to server https://developer.mozilla.org/en-US/docs/Web/API/FormData/Using_FormData_Objects
Deets for opening an iPhone app from browser: https://developer.apple.com/library/content/documentation/General/Conceptual/AppSearch/UniversalLinks.html
Factory iOS audio recorder app name 'Voice Memos' - http://www.imore.com/voice-memos