Tap a number to fill it in (must be further along the row than your last mark) - tap again to cross it out instead (scratched, doesn't count), tap once more to clear it.
Everyone can see everyone's sheet (just like the real game) - use the "Sheet" dropdown to switch who you're looking at. You can always mark your own; the host can mark anyone's.
Once you've filled at least 5 numbers in a row including its final number, the lock becomes available - claiming it locks that color for everyone, just like retiring that color's die.
The game ends once 2 colors are locked, or someone hits their penalty limit - the host clicks Finish Game when your table's done; whoever has the highest total wins.