Another tool that I wanted but couldn't find, RunTools is a set of calculators that allow you to do pace calculations, time additions, and other running-specific operations with a more streamlined interface and fewer taps.
This app was developed by Lily Gentner as a tool for runners and coaches. No data is collected.
I am actively working on developing new features for this app. If you have any questions, comments, or suggestions, please email me at firstname.lastname@example.org.