Great! Spice on iOS.

This is a very well done full fledged spice frontend that has remarkably good performance despite being on a mobile platform. This may not include real part models (LM324 op amps or IRZ44 mosfets) though you can add your own subcircuit parts easily. The live current flow works great, though you need to adjust the time step to a much smaller interval than what the simulation otherwise needs to get it to work really well - which is to be expected. Its great for teaching or visualizing filters or switching circuits. Just remember to use electron flow - it actually reflects reality and the pin names of semiconductors only make sense in this context. The "convention" is looking at the flow bubbles instead of the flow of the water itself.

Metacollin about iCircuit