Greasy Fork is available in English.
Tracks the amount of friendlies and league matches (Senior/U23/U21/U18) played by each player during the current week
After installing this userscript, there will be a button on the friendlies/challenges page (https://www.managerzone.com/?p=challenges). Clicking it will display a table with your players and the amount of matches that count towards the form played during the current week.
It is recommended that players should play 6 matches that count towards the form per week. If the player is attending a training camp via availability chip, he can play any amount of matches without becoming unfit.