Nuclear Readout Japan
Online help
The Settings page should look something like this:

There are four options you can select.
"Keep current map settings on exit"
When checked, the App remembers the state of the buttons below the map.
"Center on sensor if selected"
When checked, the App always centers the map on the currently selected sensor.
"Start in Fullscreen-Mode"
When checked, the next time you start the app, the app is started in Fullscreen-Mode which means the area usually occupied by the Notification bar can entirely be used by the app.
"Always center on location when location changes"
When checked, each time your location changes, the map centers on that location.
Further options are explained here when new versions are released.