When Lansweeper scans a Windows computer, it detects the currently logged on user and adds a logon event for this user to the tblCPlogoninfo database table. The logontime in this table reflects when the computer was scanned and the user detected. The following cleanup option under Configuration\Server Options affects how long logon information is kept in the database: "Delete logon information after XX days".
While we cannot provide support for creating custom interfaces, database connection details can be found in the Program Files (x86)\Lansweeper\Service\Lansweeperservice.exe.config file on your Lansweeper scanning server.