How have I NOT joined this place sooner?
FF.net's been my mainstay for posting fanfic since sophomore year of high school (!), but archiveofourown.org actually allows people to download stories to their phones and stuff. The layout is awesome sauce, allowing for multiple tags, multiple charcater/pairing options. You can even save a draft of a story withotu posting for up to 30 days--which is great, since I had one to post on Valentine's day and will be on duty and away from my house, so I can hit the "submit" button from a computer on the ship.
And also, I can frigging download those wonderful but long stories that I'll not want to sit up on a computer to read, such as The Roots of Heaven and that Winter War AU that's been the only fic still updated on kurosaki_clinic
I assume most of you may have accounts over there, but if not, I can't recommend it enough, and will be more than happy to send invites!