I used to teach English to non-native speakers. All of them wanted to learn English with an American accent. I think they are actually doing themselves a disservice because they fail to understand the subtle differences of class status an accent signals. A more British inflected accent is an easy way to signal higher education and status to an American. They go a bit gaga for British accents. It's also easier to fake a British accent.

The weird thing in the Middle East is (outside of Saudi) most of the formal instruction was in British English, but everyone watched US tv, and the demand was generally for a American English (even after 9/11 and the unwelcoming US immigration policy).

Same thing in China and Thailand; I don't know about other countries.

European with a British accent representing.

More anecdata for you.

"Your anecdotal evidence is wrong - I want the opposite"

"No, your anecdotal evidence is wrong."

"My anecdotal evidence is right."

The context here was "people who are having a hard time working in the US tech industry/being funded by US VCs due to accents". Obviously if you intend to work in the UK or another country which uses a different accent, it makes sense to learn in that accent. IIRC the phone bank people in Asia actually train people in specific accents based on the client for this very reason.

(A totally fluent UK/IE/etc English speaker probably is fine in any context, but I don't think someone learning from a webapp is starting from that point. If you are going to be a moderate speaker, it is better to be moderate in the target accent.)