In the "V" menu, where there normally is the reload button (next to the bookmark button), while a page is loading there's instead an 'X' to stop loading the page.
This feature has been implemented. At least to an extent. You can enable it from Settings > Privacy > Privacy and Security > Clear session browsing data on exit.
You can choose to delete:
Browsing history
Cookies and site data
Cached images and files
and
Close all open tabs.
Is this enough to mark this feature request as 'Done'?
Thank you to everyone involved in making it happen!
To elaborate on the login issue you mentioned for some sites - I found the login field isn't properly recognized on https://1password.community. Vivaldi lets 1Password autofill the password and I can see the username in the pop-up, but it doesn't actually fill the username. Both username and password are autofilled on Android when using Google Chrome, but not Vivaldi.
Since 3.8, after Vivaldi has been updated, a new tab (https://vivaldi.com/android/new/) opens with release highlights. At the bottom there are links to the release blog and full change log as well.
@axygzr991 The translation feature can be tested on Android Snapshots now as well, from Vivaldi menu > Translate. To change translation settings go to Vivaldi menu > Settings > Language settings.
@Naal The QR code scanner is already available in private tabs in the Snapshot version of the app, so it will be included in the Stable version of Vivaldi on Android soon.