How it works. A sheet auto-saves in this browser once it has a hero name. Renaming a sheet renames its save. Use the tabs to move between the three pages. Print prints all three pages of the current hero, one per US Letter sheet, and Print Blank prints an empty set. Export downloads every sheet as a JSON file and Import merges a file like that back in (a sheet with the same name is replaced). Nothing leaves your browser.
Worked out for you. Shift Labels moves one Label up and another down, and refuses a shift past +3 or β2 (mark a condition instead) or one that touches a locked Label. The Roll Helper shows 2d6 plus the move's Label, with β2 for the matching condition; Take a Powerful Blow adds the number of conditions you have marked instead. Add +1 yourself for Influence over your target, Team spent on you, or anything forward or ongoing. See Labels, Conditions & Moves, Playbooks and the Dice Roller.
Sample sheets. Load sample characters adds the 20 heroes from Sample Characters (two for each core playbook, in four teams, with each team, its origin and every creation choice in Notes), replacing any saved sheet with the same name just as Import does and leaving your other sheets alone; you can also download the sample sheet file and import it yourself.