Sorry for the latest problems with iOS11 and macOS High Sierra. It is not only Near Lock, other apps using Bluetooth Low Energy are also affected. Both iOS11 and macOS High Sierra are having updates which affect Near Lock.
I promise I will do my best to have a working version as soon a possible.
The screensaver lock option is not working - for now change it to sleep instead but a new update will fix this.
P.S. Sorry if I haven't responded to all your emails or messages. I'm working hard to get it working nicely so don't have som much time to reply to all requests. But all your emails will be answered once a new version is out!