Paying software to locate a phone are in full swing, and quite expensive.
We were curious to see what we can do, and if possible free of charge
Best combination nearly for free is :
(an internet connection is needed on both sides, wifi or data), we recommend only leave wifi always enabled, but leaving data always is best of course to track at maximum... but will cost battery, and health injuries to the mobile phone holders...
To avoid having Internet connected (unhealthy for adults-children like plan 1) since it is needed for getting back GPS location, you can get location instantly on request by SMS :
(For this one, only a phone plan with SMS included is needed) and some € for app...
(For a few more €, possibility to automate at regular intervals)
For those claiming to be protecting from kidnapping, this is fake to the extent that is mobile phone has no battery, or was turned off, you can't get back anything neither from plan 1 or 2, the best you can get is from plan 1 with last locationregistered (mode if data was enabled) and if there was an internet connection turned on... Plan 2 with automation is pretty good also...