I haven't seen this option for android phones listed so thought I would add it in.
On my phone I have it so that my spouse can send me an text with a specific keyword and it will send her back my current location in a google maps link.
This is accomplished via an app called Tasker for android phones. It's provides infinity more flexibility that a find my friend type app. It takes a little more effort because your have to program it, it's not hard and lots of existing scripts are out there already, the benefit it it will do exactly what you want.
In my case it will only send my location to my spouse and only when she texts my keyword but that came be changed to just about anything you want depending just by changing the script.
For those out there in the Android world.
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