Commander Damage Tracking
Tracked per source and per target, the way Commander needs.

Commander damage is a matrix, not a single number. Manatable tracks it that way: damage is recorded per source commander and per target player, rather than lumped into one running total that loses the detail you need mid-game.
Each commander's damage to each opponent is tracked separately, and it is lethal at 21, per the rules. Manatable checks the threshold automatically, so no one has to do the math three turns later.
The N×M matrix on a phone
A four-player pod with two commanders in play is a grid, not a line of text: every commander against every opponent. Manatable lays that matrix out for a phone screen, so you can see who is close to dying to whose general.

Partner and background support
Running two commanders? Manatable tracks each one's damage separately. A partner pair, or a commander with a background, each deals its own commander damage to each opponent, and each is checked against the 21-damage threshold on its own.
Commander tax
Casting your commander again gets more expensive every time it returns to the command zone. Manatable tracks the cast count per commander and applies the current +2-per-cast tax automatically, tracked separately for each partner commander just like damage.
So a two-commander deck sees two separate tax counters, matching its two separate damage counters.
Fits the rest of the board
Commander damage feeds into life tracking's elimination logic: hit 21 from one commander and you are out automatically. Because seats matter for who is hitting whom, it works with seating, especially the 5 to 6 player radial layout, where tapping an opponent's slice brings up their damage controls directly.