Tread

Tread keeps an honest count of the miles on every pair of shoes you own. It reads runs, walks, hikes, trail runs, stairs and elliptical sessions from Apple Health and asks which shoes you wore, from a notification, the app or your wrist. Set a retire-at limit per pair and it forecasts the week you will hit it, warns you at 90 percent and keeps retired shoes in a history with final miles and cost per mile. Usual pairs are picked per workout type, workouts can be split between pairs, and a photo turns your shoes into a sticker. It has Apple Watch and Home Screen and Lock Screen widgets, and no account.

Its description lists workouts and shoes side by side on iPhone Duo. Its maker's site shows Workouts on the left of the open Duo, with this week's miles and the runs and walks that need shoes, and Shoes on the right, with the next pair up, the pairs in rotation and their mileage bars and recently retired pairs.