"I'm a Nay Saying worm beast!"
So there are tools out there to emulate a Game Master for solo RPGing but are there any for emulating a player? The idea just occurred to me and I thought it would be fun to brainstorm a bit on how that could be done.
Since GM emulators mostly work by answering to specific questions (such as "Is the chamber empty?"), I suppose you could just use a normal GM emulator, only adjusting the questions ("Are the PCs taking the left or the right door?").
But seriously, I think you are misinterpreting the role of GM emulators and the experience of playing with them. It's not like you are the player waiting for the prompt from the emulated GM to react to. The thing is more akin to prepping, mastering and playing all rolled into one.