GPIO protection module advice?

[datguy.dev]

Greetings,
Short and simple, I'm working on a project that let the public poke around an RPi unsurprised. They can't add anything to the project however, so we'll be working with 5v at the most to power some senors etc. Obviously, I have a need to protect the public from shorting out the board; whether that be connecting two 3v or 5v into a gpio or gnd. Frying the pins or shutting down the device would be unfortunate.

I was looking for a module that would offer this functionality, but it has been slim pickings. I don't really have the time to make a circuit. Do you have any suggestions or perhaps comments on Protect Your Pi?http://www.elecrow.com/protect-your-pi- ... p-745.html

Mant thanks! <3