https://random.bretpimentel.com/ has the option to change to a random note every 1-5 seconds
The trickiest bit for me has been getting split mentally between picking between 5th & 6th strings to play the note and getting neither right in time XD
Knowing the notes on first five frets is part of Grade 2 which I knew I need to work on even though I had passed Grade 2. Started working up the Fret board learning just the main note positions as I can work flats and sharps from these.
I am using Justin’s App to test myself and it is working well for me.
Michael 
I used to spend a lot of time counting through the cycle of 5th starting at C by counting though the 5 fingers of my hand from C to G and then from G to D and then D to A and finally from A to E and E to B. That’s the sharp keys from no sharps on up.
Notice that the essential 6 notes going up the fretboard by pairs of 6 and 5 string notes is CG DA and EB, the circle of fifth notes starting from C and going to E.
It was useful for me to count this way on my hands too, because it helped me memorize the I IV V chords. Notice if you memorize the essential 6 notes this way, each note from G to E is surrounded by its IV and V chords.
I should add to the last posted message that I had just realized that the 6 essential notes are the circle of 5ths from C to B. I didn’t recognize that when I studied the notes for the power chords in the classic beginner course. I am almost there in the new beginner course. I knew that the notes on the 6 strings on the guitar are tuned a 5th (correction: 4th, see below) apart except from the 2nd to the 3rd string. If you play the C (2nd string, 1st fret) and strum all the strings to the lowest note you go C G D A E. I read that some jazz players tune the first 2 thinnest strings to F and C so that the strings are all a 5th (correction: 4th) apart and riff shapes work on any two string. Anyway I have been noticing the C G D A E pattern on the guitar more often and in this case it helps me remember the 6 essential notes better than a mnemonic.
@SteveL_G99 you have it backwards. A guitar is tuned in 4ths and the B string is tuned in a 3rd. E to A is a 4th
You are correct in this statement but that’s not how a guitar is tuned. It’s tuned E A D G all 4ths G to B is a third B to E is a 4th.
Steve, when you reach the circle of 5ths lessons in Justin’s music theory course (module 4) you may also wish to extend your depth and breadth of understanding by reading my tips topics which start here: The Circle of Fifths Part 1 - where does it come from?
Cheers 
| Richard_close2u | JustinGuitar Official Guide, Approved Teacher & Moderator
@stitch That is true if when you are starting from the lowest string which is the standard and preferred way of viewing the string tuning. But if you start from the highest string and work backwards the intervals are fifths except from the 2nd to the 3rd string. I was going in that direction on purpose to show the relationship between the open string orders and the circle of fifths. Going from G to D is a fifth, from D to A is a fifth and from A to E is a fifth.
Counter-clockwise the circle of fifths becomes the circle of fourths.
@stitch I couldn’t end this discussion without admitting that you are 100% correct and I I know better. I first learned to tune the guitar by the 5th string tuning method, where for example the fifth fret of the low E string is the note A (the 4th above E) which matches the A of the open fifth string. I was guilty of sloppy thinking in introducing the idea of the tuning of the strings. It is just the open string sequences a letters that can match the circle of fifths in the clockwise directions from G to E. If the first and second string were to be tuned to C and F you would have all the strings tuned by 4ths, which I heard is used by a few jazz players that are exclusively single note improvisers. It would make chords more difficult 
I think the thing that contributes to my sloppy thinking is that the strings are numbered 1 to 6 from highest to lowest pitch strings. You would think it would be the other way around since the strings are tuned up from the lowest strings and the pitch is ascending from the lowest string and the lowest string is on the bottom in TAB. The only way it is ascending is by altitude or height since the highest string is closest to the ground when playing the guitar.
The strings are also numbered in ascending string thickness
I’ve started module 12 and this lesson complements the power chord studies. That is one of the main reasons I was forced to go back to beginner lessons after starting intermediate. I really never learned the notes on the 6 and 5 strings without a lot of hesitation. That and going so long without playing the guitar that I lost all of my calluses
After studying the 6 essential notes I though of a mnemonic. The GC made me think of guitar chords so first I thought:
Guitar Chords
Are Demonstrated
By Example
But that seemed redundant and a little forced, so how about this:
Guitar Chords
Are Done
By Everyone
@Konstantine236 When you get to module 12 in grade 2 and start practicing power chords, perhaps this lesson will make more sense, if you mean that you don’t understand why you would learn this or how it is used to play guitar, although Justin does discuss this in the video intro.
@Richard_close2u I took a quick peek at your open topic discussion on the circle of fifths and admit that most everything beyond the color wheel was beyond my level of understanding but I look forward to reaching that level of understanding in the future.
Maybe three green colours, as in imagine a traffic light with green lights only? I think its easier to imagine thatt than the emotional state of three cats haha
I used Fachords Fretboard Trainer. It rocks.
Currently I’ve got all the notes on the 5th and 6th strings.
I’ve been working on notes including sharps and flats between the 3rd to 7th frets.
My last recorded session was about 2.5 seconds between correct guesses. Part of the time is moving the mouse and clicking on the correct note.
I’ll be adding additional frets too. I’ve got all the notes on the 10th fret memorized too, so I may now move this exercise to go between the 6th to the 10th fret and work on speed and accuracy.
If anyone want to try it, go to the link and hit “Easy Mode” to set up the fretboard limitations.
Fyi, I’ve no connection to that site, I’m just a fan-boy. It’s a great tool.
Is it just me or is the diagram upside down? Shouldn’t the low E be on top? 
Were you to take a print out of TAB and place it flat on a desk, then place your guitar flat on the desk in the manner you play it, with you sitting at the desk, both would have the low E / thickest / 6th string nearest to you. The orientation of the TAB will not always be flat depending on whether you read it on a computer screen, a music stand or other. But the same principle applies regardless of the orientation.
Hope that helps.
Cheers
| Richard_close2u | JustinGuitar Official Guide
thats great thanks
Just throwing my mnemonic in here, since I couldn’t get the others to stick in my head: Groovy Chicks Always Ditch Bad Eggs. (I didn’t do anything with the numbers because 3-5-7 is easy to remember and they all have dots on anyway)
