Miataru or 見当たる is Japanese and means "be found" or "to come across" and its meant to be a set of tools to allow the user to track locations and choose how to work with the data as well as how data is stored if at all.
This is the Miataru iOS App that allows you to use the free Miataru service or your own Miataru server instance.
Disclaimer: Continued use of GPS running in the background can dramatically decrease battery life.