If you didn’t change the name of the file you downloaded and setup for autostart… well the version is in the name 
Also, if you manually start LS from a terminal window, after a few seconds it will tell you that it started and what version (usually a newer SNAPSHOT)
Otherwise if you did change the name to something generic… then look at this Topic.
So then go down the list… confirm
- LS version 0.3.x
- App 2.18.x (Android)
- Proper IP and port (9443) in App’s custom login
- Port property forwarded in router to LS IP (This may only be applicable if your app connects from outside of your local network)
If still issue, but only on one phone, then completely remove and reinstall App.
I can’t think of anything else off top-o-me head