I dont seem to understand what a tuner pedal is.Does it indicate when some string goes off tune or something?
well to simplify
A chromatic tuner ir tyber pedal is one which can tune any note (C,C#,D,D# etc.).
its very usefull if you go out of tune when you are on a gig, so you dont have to waste time, unpluggin the guitar and plug it to a tuner.
its easy to work for exemple
you have the 11-point Stream Meters, when you hit the green point it means that you are in tune to that note. if you have to much red points on the left of green light with means that you are out of tune to that current note, if the red points are on the right you are getting also out of tune to that note that you want.
sorry maybe hard to understand ,...but i have also a hard time to explain T:T since im not very good and clear with english lang.
PS: for a better understanding i recommend you watch some youtube vidios q: