For skill tracking (but it could word for habits too), I use this spreadsheet I made: https://docs.google.com/document/d/1zn78PfhgxFnVEUUlgZrew7xbzOYjugNJ3PrYIC1-yyY/edit?usp=sharing. You can download a copy and edit it.

For habits, I can recommend Way of Life: https://wayoflifeapp.com/. I usually just mark it on a calendar, or more recently, in TeamWeek.

Hope this helps!