A few minutes ago, after many weeks of work by @a.cappelli87 and myself, location sharing branch was merged. It will be available in the upcoming 4.1.0 release with many other improvements and fixes. We’ll probably do a beta release first though - both Google Play and F-Droid.
My spare time is very limited at this time, that’s why my presence is so scarce and I’m sorry about that, I’ll try to be more present and productive. I want to see Kontalk grow too 
See you soon for the next release.