It's worrying that any website can access real-time data from sensors by default in Android browsers, and there is no option to deny access to these APIs in Firefox for Android and Samsung Internet.
https://support.mozilla.org/en-US/kb/firefox-protection-agai...
This feature is enabled by default on some Firefox forks like Mull.[1] On Android only, the release channel of Firefox disables about:config entirely,[2] but Firefox Beta and Nightly have about:config available.
[1] Mull: https://f-droid.org/en/packages/us.spotco.fennec_dos/
[2] Please vote to remove this ridiculous restriction at https://connect.mozilla.org/t5/ideas/firefox-for-android-abo...
I placed my phone on the surface. And did see the numbers jank when I started typing. Then I left it at rest and said a loud "Booo!" and saw the numbers jump again. To confirm, I'd need to plot the numbers and do some statistical analysis, which is far too much work for me now :D