This app is designed to track family member, couple, your sweetie. This is not for finding lost phone.
You can try this app for 14 days. If you like it, please purchase premium upgrade license.

It shows where he/she is on the map by inquiring location of the target device. It tracks location only when you ask for it.

-Location can only be tracked between devices which owners have agreed and registered as member by sharing passcode.
-Since it based on Google's push service, battery consumption is very low. And no need to run this app beforehand. Just install and setup.
-It never uses mail or SMS for location inquiry. (It may use SMS for phone state inquiry.)

*List of reason of permissions can be found at:
http://file.blog.fc2.com/nekonotesoft/manual/imadoco-en.html#Permissions