XnView, Irfanview and FoxitReader are not signed

Hi, I was just installing the latest versions of my usual software, but Windows has warned me that, unlike all the other portableapps installers that I just downloaded, XnView, Irfanview and FoxitReader are not digitally signed. I double checked by looking at the file Properties for each.

Is this intentional? Do I need to worry that these installers might have been tampered with? Did someone just forget a step when packaging the latest versions of these apps?

Is this the right place to bring it up, so that the issue can be fixed?

Thanks