Best coach & referee scoreboards & timers according to redditors

It looks like this

You press the button and it counts. It makes a satisfying click so that your submissive can hear that they just earning another :)

GymBoss is a good cheap one.

Search Amazon for a boxing timer. We have something like this, but ours doesn't have the lights and it has adjustbale rounds: http://www.amazon.com/Title-Boxing-TITLE-Classic-Timer/dp/B00FJBFHIK/ref=sr_1_5?ie=UTF8&qid=1398194375&sr=8-5&keywords=boxing+timers

Also, if there is a stereo available, you can just download an interval timer app and plug your phone into it. Or rely on the external speaker on the phone, but that can be hard to hear in a crowded gym or with music on.

A Pitch counter is a lot cheaper, if this is just for your own personal use and not display.

STEELMASTER Tally Counter, 2.75 x 1.5 x 2.75 Inches, Silver (200100492) https://www.amazon.com/dp/B0089KJSFQ/ref=cm_sw_r_cp_api_i_fdYtDb1B1SMCG

I did find these on amazon. I’m going to give them a whirl. Looks almost the same

Manual Scorekeeper with Adjustable Stand

Here is my current go-to scoreboard & it's pretty huge for carrying around. Something as durable/visible but more compact/portable would be awesome! It's nice to have it be tall when set up, for ease of visibility by players on opposite sidelines, so perhaps some sort of telescoping legs.

I like mine and have it mounted on my wall. I can also detach it easily if I'm doing a set somewhere else.
https://www.amazon.com/gp/product/B001E6BWSS/ref=oh_aui_search_detailpage?ie=UTF8&psc=1

A Champion Sports Dual Timer. It serves its purpose of helping me time workouts and various other things. The design is slightly flawed in that the timer actually has a hard time standing upright, but otherwise it's pretty cool...for a timer.

I've got a manual clicker counter, but honestly I prefer to have an empty hand so I count most of the time. It gets more automatic over time. I mostly focus on my music 'til I get to my starting point.

From Amazon

They have something like this inside (but way more sophisticated) that keeps track and then the information is downloaded when they are picked up.

You could go uber-tactile and get a tally counter like umpires use. Just imagine that satisfying click when you raise your threat level (or, I guess, the annoyance of having to do it about 30 times at the beginning of each game).

I bought this one new on Amazon, but havent received it yet. I dont do Crossfit workouts, so just need the clock and for it to count down 3 minute intervals of rest between powerlifting sets