looking for Google free tracker

Hi everyone,

my cat is becoming increasingly adamant about going out. For health reason I can't walk her on a leash enough to satisfy her. So I'm looking for a tracker for her which works without google (in Germany).

The best option I've found so far is nut tracker. It also uses googlemaps but has a screen where it shows when the tracker is near and can beep the tracker.

Do you guys know of a better option?