is there a device that will read frequencies from a variable 555 circuit and display them on a digital screen?

 

That would be a frequency meter.

I've used some Fluke handheld multimeters that have such built right in.

 

Yes, it is called a frequency counter.


Some digital voltmeters can do this as an added function (Hz is usually the symbol on the function selector).

 

Thank you for that, you can probably see the level of my experience.
I am also looking for a screen that I can build into the finished circuit so as the pot is turned the frequency shows up on that screen. so anyone using it can play with the frequency.

 

Yup! Frequency counter.

 

Here's a couple of links to frequency counters you can build......

HTH Steve

 

thank you all. I will research this