The iOS port includes touch controls, and supports the original game's feature that lets you anonymously interact with another player online.
In the game, you play as a character who is exploring the remnants of an unknown world, trying to reach a vast mountain peak. You can play the entire game alone, but if you have the multiplayer feature turned on, the game will randomly introduce companions that can aid you on your journey.
thatgamecompany is also behind "Sky: Children of Light" on iOS, which first premiered on stage at Apple's iPhone X event in 2017. Sky finally launched last month, and it shares many gameplay features with Journey.
You can download Journey on iOS for $4.99 [Direct Link].