Jade, a new title set in China, is one of the titles that will be returning to mobile devices. The game takes place in the year 215 BC and is designed to feel like a mainline entry. The classic eagle-flying-over-a-settlement sequence is the only thing that has been shown.
It will be the first time in the series that you will be able to create your own character. There is no word on how much the game is going to cost.
For nearly as long as the series has existed, the publisher has tried to make the game available on mobile devices. The first mobile game was Assassin's Creed: Altar's Chronicles, which was released for the Nintendo DS in 2008. In 2007, the original Assassin's Creed was released for the PS3 and XBOX. Since then, there have been a number of mobile-first Assassin's Creed games, but the series hasn't been released on any of the mobile platforms.
The live-action Assassin's Creed series is going to be the basis for a game. There's also a new mainline title called Assassin's Creed Mirage.