I just installed the app and took a look.
I find it a PITA to have to enter all the details for a vehicle each time it is used.
also, the 2D view is almost useless to find a vehicle in reference to where you are.
Compare to this app which is my default 'find my car' app. it gives me 3D view as in Google Earth.
I can actually determine which parking spot the car was left at.
https://play.google.com/store/apps/details?id=com.nomadrobot.mycarlocatorfree
As for locating a friend?
that is going to eat up a lot of DATA, and if you are on a limited DATA budget as most of us are, the app won't ever be used. My daughter and I share a Family dataplan. no way will we ever use something like this. We have to keep our data below 1 gB/month. We never surf away from home, WiFi only.
I find it much better to use a Macro such as MacroDroid can provide which just simply monitors SMS messages searching for a phrase, ie, "whereareyou" and it then turns on the GPS, gets the current location, and then sends a google link back so the requestor can use their data/WiFi to look at a map and see where you are.
This is just one user's opinion, but this app will burn up battery and data faster than normal.
I don't see it ever getting a lot of use.
FWIW, YMMV, and my opinions are my own, and worth every cent you did not have to pay for.