I use some fitness equipment to track progress and I also use the official LEJOG challenge by The Conqueror app on my iPhone. This is an app that automatically ingests data from Apple Health (or other sources) and tracks that data against your chosen challenge. They have a raft of them, from The English Channel at 21 miles, all the way up to The Pacific Crest at 2,485 miles. I did one last year as a walking challenge during lockdown to help get me out of the house.
I like the app and the program as you get virtual postcards at certain points on your route that give you fun facts, and also the company will plant 5 trees during the route. So I’m contributing something back to the environment. You also get a very snazzy medal upon completion and a free t-shirt with your route logo.

This image is day 1