|A number of angels are mentioned in the Koran|
Islamic angelic tradition is pretty sparse. This is because, unlike Christian and Jewish religious scholars, Islamic theologians do not consider the study of angels as an important topic. In their opinion, if the Koran does not directly talk about a particular subject, there's no need to study it. Of course, there's a hierarchy, but they are of the belief that it's none of their business. Why worry about something that's not broken after all? Besides, angels have no free will - they do everything that God commands, their supernatural powers focused on their goal.
There are, of course, several angels named in Islamic tradition, each accorded their duties by God. Some of them are actually quite familiar. Jibril is Gabriel, transliterated in Arabic, of course. His job is to be God's voice to his prophets. He was the one who delivered the Koan in its entirety to the prophet Muhammad and this has made him a pretty honored angel. Another familiar angel is Mikaaiyl or Michael as we know him.
Instead of being Heaven's general, in Islam, he is the angel of mercy, dispenser of rain, a very big thing when you're living in the desert. He's also in charge of the just reward of virtuous people, a long way from the demon slayer of Christian tradition. The name Israfil sounds unfamiliar, but just take out that initial "is" and you get Raphael. He's got the dubious honor of blowing his trumpet that ends the world on Judgement Day.
Of course, there are some original angels among the bunch named in the Koran and in the Hadith, the oral stories about Muhammad. Probably the most famous is Malak al Maut, the Angel of Death, though popular tradition calls him Azrael, which is strange considering he isn't even named in the Koran. His job, if it wasn't obvious enough from his title, is pretty much to take the souls of people at death to be judged.
Other angels mentioned in the Koran are Maalik, the guardian of Hell, and Ridwan, the keeper of Heaven. Note that Maalik is not a fallen angel. Islamic tradition states that angels cannot fall because since they do not have free will, they cannot rebel. Maalik's there because Allah wants him to make sure that no one escapes. He stays there with nineteen other angels to make sure that sinners receive their well-deserved punishment. Kiraamun and Kaatibeen double-team to record all the good and bad deeds a person has done, while another pair, Munkar and Nakir interview them in the afterlife about it.
As is typical of angel imagery, most Islamic sources describe angels by their wings, though some of them can be overkill. Two to four wings is the usual count, but Gabriel and Michael are said to have thousands of wings sprouting from their back, signifying their power and position. Some aren't even human in appearance - 70 thousand headed angels are said to sing praises to Allah in Heaven.
All in all, you can see how differently Islam views its angels. It's like looking at a weird fun house mirror - there's a certain familiarity that we can almost recognize, but there's a telling difference in the way we see things.