Found a couple things. There are some pricey e-books on prismatext.com
based on popular works in the public domain (Sherlock Holmes, Jules Verne, Charles Dickens…) The text is almost entirely in English, with a few sentence fragments translated into the target language. The reader is encouraged to first try to feel what it means from the context. You can click on any such fragment to get the translation. Seems like an OK idea for people who want to learn a bit with practically no effort and who are already interested in reading the particular titles, but surely this takes forever compared to doing flash cards. There's a free demonstration of the approach, the short fairy tale "The Emperor's New Clothes". I don't have the impression that much thought went into making these. The same books are offered in variations for many target languages and going by the demo it seems that no matter the target language, they are almost entirely translating the same set of words. I suspect they made their choices based on minimizing vocabulary overlap for those who buy several of their titles with practically no consideration of how English and the target language relate to each other (sound shifts) and how long words are often made of meaningful components.
I suppose one could make a browser plugin that does the same as prismatext. (I think a great approach that doesn't slow down reading too much would be to only translate words that already appeared among the 20 words or so before and just highlight that earlier word when hovering the mouse pointer.) Perhaps something like that already exists.
There is a book called "Spanish Stories" by Angel Flores
that has a very good choice of stories in Spanish with English translation and information (in English) about the authors. However, it is rather complex Spanish and the translation is not presented in the most direct fashion sentence by sentence. So reading this is not easy. There is also an appendix with translations of some
words (it is assumed that you already have the most basic vocabulary down). It's better to read the paper version of this than the ebook.
The ebooks on interlinearbooks.com
use the best method of directly showing the gloss under the text in the target language! I haven't read anything by them yet except the screenshots on their website, but this looks very promising.