We do not have a download file for the latest version (8.1.6.314), but you can try downloading it from the developer's site
Download version 2.7.1.1 from Software Informer
Scanned by 75 antivirus programs on May 25, 2023.
The file is clean, see the report.
Version: 2.7.1.1 (x86)
Date update: Jun 28, 2017
File name: sd8_smartpdf.exe
Size: 12.8 MB