Every DCC modeller has done it: spent an evening getting a locomotive running exactly right, then months later changed one CV and lost the setup you can no longer remember.
Get it on the App Store What it doesiPhone, iPad, and Mac. One locomotive free — a single lifetime purchase unlocks an unlimited roster.
CV numbers, values, and your own notes for every locomotive. Indexed CVs are supported.
Save the current state under a name you will recognise, compare it against what you have now, and put it back if the new values are worse.
Set direction, speed steps, and address length with switches. The app works out the value and leaves the reserved bits alone.
Record what F0 through F28 actually do on each locomotive, with notes.
Bring in locomotives from a JMRI roster. Every import is previewed before anything is added, and you choose how conflicts are resolved.
Export one locomotive or your whole roster as plain JSON you keep. No account, no analytics, no advertising, no server.
An unknown CV is not a CV set to zero. A value you have not read yet stays marked unknown and is shown differently, because guessing it is worse than admitting you do not know it.