Previous releases of jammr, including 1.3.0, were not signed with a code signing certificate.
The jammr 1.3.0 installer for Windows has now been signed. Future Windows installers will be signed by “JAMMR LTD” so you can be sure the software has not been modified (e.g. infected with a virus).
There is no need to re-install jammr if you already have 1.3.0 installed. If you have a previously-downloaded jammr 1.3.0 installer for Windows you may notice that a newly downloaded Jammr-installer.exe file is now different. This is expected because code signing affects the contents of the exe file.