Simplest way to add Mileage in iPhone.

Simplest way to add Mileage in iPhone.

It was easy for me to record Mileage expense in android Phone as it had options to add mileage along with the Record Expense Menu. 

While the same was not available in iPhone. It had only record expense or Add report option when clicking the Plus button. 

What is the simplest way to record Mileage using Location in iPhone?