After a lengthy members-only beta, Old School RuneScape has finally launched globally for all mobile users, regardless of their OS of choice.
For the unaware, RuneScape is a long-running browser-based MMORPG which lets players train a wide variety of skills, embark on epic quests (which are always more involved than "go here and get that"), and slay powerful beasts.
Old School RuneScape (OSRS) is a separate entity, maintained by a separate team of developers. Essentially, the game is an official recreation of RuneScape's 2007 state; graphics and all. It gets its own major updates, world expansions, and features.
While the mobile and desktop versions of OSRS are now free to play, don't expect the same experience as paid users. There are quite a few restrictions in place - for example, many quests, zones, items, and monsters are members-only.
However, if you've never played the game before, there's still plenty of content to chew through as a free user. There should at least be enough to keep you occupied for a few weeks while you wait in lines or take the subway to work.
Cross-play is, of course, supported here. You can log in to the desktop version with the same account you created for the mobile version, and vice versa. All of your progress, including your character's location and friends list, will be saved.
Furthermore, when logging in, you occupy the same world as PC users. While this might give them a slight edge in PvP, it's a nice boon for chatting with PC players as you chop trees, go fishing, or take part in other non-competitive activities.