Revolutions (pulse) per minute counter circuit?
Yes, lots of people I suspect.

However, using a microcontroller would be a simpler way.  In a micro you can count pulses in a known period, or measure time between pulses.  Counting pulses within a period is simpler, but can take a while to get a meaningful reading or you have low resolution.  Most of the time you measure time between pulses and then invert to get speed.

Many micros have a capture capability where the value of a free running counter is captured in hardware when a pulse is received.  By subtracting the previous capture value each pulse, you get a high resolution measurement of the period between pulses.  I'd low pass filter that a bit, then invert when needed to update the user interface to show speed.

The 7 segment display encoding is also something the micro is well suited to do.  It can then perform the multiplexing on the multiple digits, or you can get a micro with lots of I/O lines and hook up each segement individually.