An application that proposes an estimate of TDEE (Total Daily Energy Expenditure) based on a person's step count and offers to track TDEE over time.
This app is an alternative to other TDEE calculators online that use vague descriptors of activity and the amount of walking that a person needs to achieve each day in order to burn X amount of total calories. Here, the equation is simple - BMR (energy burned at rest) + an estimate (!) of calories burned by walking X steps at an Y pace.
TDEE can increase/decrease over time, which is why the app is going to also offer to track a user's TDEE over time based on their weight change (or lack thereof).