at the lower section fo https://www.kismetwireless.net/downloads/ the source code of the Smarter Wi-Fi Manager app is still available (as the fdroid site mentions that the source not retrievable anymore). However I do not know which version it is.
The Kismet legacy code was last released as a stable version in 2016; this code base is aging, but my in some cases be more suitable. This version is being phased out, and does not include the web UI, JSON output, unified database logging, or any of the other new features of the latest beta and development code.
Duno, if this is related to the “Smarterwifi” app, but the latest revision is “2016.12.85” and the last F-Droid build is Version 2016.12.85 (85) - Added on 2016-12-25.
The App is still up to date.
However, there is a branch titled “swm2” (net.kismetwireless.android.smarterwifimanager2), with the version pushed to “2018.05.90”