Go to a song and tap the Edit (pencil) button on the top right corner and tap on Edit, Duplicate or create a new song from a template.

Check out the new Editor which consolidates all symbols into one keyboard.

Available in iReal Pro 2021.7 for iOS and iReal Pro 2021.8 for Android

(minimum requirement: iOS 13 & up and Android OS 8 & up)

Tap a chord to edit or delete it and enter a new chord.
The '...' Quality button will show you a list of available chord types.
(example: enter the Chord 'G' and enter or select the chord quality like 5, +, 7, etc.)
To change the quality to another, simply tap the '...' to show the quality options and tap the new one which will replace the previous.
Delete/Add space in the chart with the <- & +> arrows (more info here)
'i' Info button: allows you to edit the title, composer, style indication and the default key of the song. This style is for listing, not necessarily related to the player style.
Alternate chord: add small alternate chords above the existing chord
(Note: the player will ignore them)
Time signatures
Tap the space where it is to be added, tap the time signature to input (to delete, do the same).
Slash ( / ): indicates the repetition of what is written on the previous beat or serves as a slash for the bass note in case of inversions like G/D
Repeat symbol ( % ): repeats the previous measure
Two-bar repeat symbol: repeats the previous two bars by placing this sign over a bar line.
N.C. (No Chords): the chordal instruments dropping out for the duration of the N.C.
Invisible root: repeats the previous chord over the specified bass note and the symbol is used to make only the bass notes visible.
'S / N' button: inserts a size change of the chord in the chart.
Tap 1: small, tap 2: normal, tap 3: neutral (this size remains until the opposite size change further through the chart)
Undo button: undo your edit
Undo button
Repeat endings:
The options are 1st ending, 2nd ending, 3rd ending, open repeat (tap again to delete, it will show in blue as shown)
Rehearsal mark: A, B, C, D, in (intro), V (verse) options. The 'in' (intro) and V (verse) rehearsal marks indicate a section in the song that will only be played once at the very beginning.
Symbols button: Coda, Segno, Fermata, END
The END symbol indicates where the player should stop on the last repeat.
Tap again to delete (it will show in blue).
Barlines: cycle through the options with taps.
1st: regular, 2nd: double barline, 3rd: repeat, 4th: cancel
(Single and double barlines can be entered on the left or right of the cursor so must be deleted from the same space with the same left or right barline button. (In other words, if it does not delete, tap the adjacent space then tap (a few times) the other barline button (left or right)
TEXT mode: The 'ABC' button takes you to the keyboard to add text.
Tap on the chart to add text where the cursor is.
The 3-line text button shows a list of available rehearsal texts understood by the player e.g. D.C. al Coda, D.S. al Coda, repeat times up to 8x (for more than 8, type the number in, then add the x)
Tap either the up or down arrow move the text vertically.
Tap on Done to exit text input mode.
More information on text here (including adding a second line).
Down arrow: to add vertical space between the systems.
Cycles through - 1st tap: 1 space, 2nd: 2 spaces, 3rd: 3 spaces, 4th: remove it.)
It's often used to separate a Coda section.
You can also use them when adding a second line of text.