If you just want a timer and it doesn't need to be this "egg timer" specifically....
Making timers from scratch comes up from time to time, and it's pretty easy.
Here's a small example in the programming questions thread that would start automatically when the card is viewed.
And here's another thread talking about making timers.
If that seems like something that would work as a replacement for what you wanted the EggTimer Contraption for, then I'm very sure folks around here would be happy to answer questions to make sure your home made timer does what you want it to do.