I am fully aware that there is no way for a user to port an app that runs on Blackberry somewhere else, if not for some compatibility problems then Blackberry's strong security and encryption features stand against it. But it means that Opera could make a such a port with much less effort needed than a port of a native app would imply....
Btw. my Blackberry Q10 can do both: Android and native apps, and both could be Java..., and so far I have found no way to tell what exactly runs there... My old Samsung would indicate a running JRE with an icon, but the BB doesn't.
I learned from somewhere on internet opera has a configuration that allows them to select which website to load in what mode. Is this true?
As far as I know, yes. Sites that are known to not work well on extreme mode will be loaded using high mode.