Hi! I just moved from Kindle Oasis to Kobo Clara BW and was upset that Kobo does not have English - Russian dictionaries built-in. I didn't like the dictionaries I found online, including this thread, so I decided to convert Apresyan English-Russian dictionary from stardict to Kobo format.
dicthtml-en-ru.zip
It is a decent dictionary that many people like to use, but I'm still missing Oxford English - Russian dictionary from Kindle. I wasn't able to find it in any downloadable format to convert it to Kobo format. I found one on my Mac in form of Apple Binary Dict, but it contains a lot of html and css that are not really good convertible. And I think this will be a huge pain to convert it from html to Markdown for proper formatting on Kobo.