RCTgo

Frontier, developers of RCT3, made and recently released this iOS game called "Coaster Crazy."

Sure, it's no RCT, but it has promise and could even replace the current coaster-building system when RCT4 comes - making stretches of track which you can manipulate into turns, bank in any way possible (from a 1 degree bank to extreme 122 degree overbanked turns and more!), tilt and resize the loops any way possible, control over the direction of the coaster (no more straight/diagonal pieces and more realistic Dive Loops / Immelmanns), lift hills and LIM launch sections in any shape (I just made a vertical loop-shaped lift hill, you could even make an overbanked turn shaped lift hill, and more), the possibilities go on and on. All without rough banking transitions, and pieces, like inversions, tunnels and thrill lifts, integrate seamlessly into the custom track.

If that happens in the next RCT they should really make a better way to align polygons to the tracks, because unlimited track shapes mean that our current catwalk and custom supports / spine connectors would become useless in the new game. Here's hoping for dynamic CS catwalks/supports that changes shape to match the track spine, else I think the realism-focused coaster community would stick with RCT3.