Just finished reading Fallen and Guardian, the first two books in Claire Delacroix's Republic series. This author normally writes historical and regency romance novels. This is more an urban fantasy based in America of 2099 AD. Her main protagonists are angels that volunteer to lose their wings and complete assignments here on Earth 190 yrs in the future. That future is a bit dark with our society a bit backward due to lack of fossil fuels and several devastating nuclear attacks on various major cities in the world.
As a side note: I have noticed a bit of a trend in paranormal romances that are now featuring angels in their plots instead of vampires. Oh, the angels in these books are not necessarily all that sweet.