Which version of PHP GD Security Headers plugin requires?
GD Security Headers plugin requires one of the following PHP versions: 7.0, 7.1, 7.2, 7.3, 7.4, 8.0, 8.1, 8.2. The plugin might work with older PHP versions, but they are no longer tested or supported.
Which version of WordPress GD Security Headers plugin requires?
GD Security Headers plugin requires one of the following WordPress versions: . The plugin might work with older WordPress versions, but they are no longer tested or supported.
Which version of ClassicPress (WordPress fork) GD Security Headers plugin requires?
GD Security Headers plugin requires one of the following ClassicPress versions: 1.0, 1.1, 1.2, 1.3, 1.4, 1.5.
How old is GD Security Headers plugin?
GD Security Headers plugin is 4 years, 8 months old.
When was GD Security Headers plugin first version released?
GD Security Headers plugin was first released on March 27, 2019.
Where can I find list of changes in all GD Security Headers plugin releases?
The detailed changelog for GD Security Headers plugin is available here: GD Security Headers Changelog.
Can I translate GD Security Headers plugin to my language?

Yes. POT file is provided as a base for translation in the root folder for each plugin. Translation files should go into languages directory, and WordPress must be set to your language to load the file. As an alternative, translation file can go into wp-content/languages/plugins directory.

The file name for translated and compiled MO file must be the same as POT file with the addition of language code: {plugin-name}-{language-code}.mo.

You can check out this for translating plugins using POEdit program:
support.dev4press.com/kb/article/translating-plugins-or-themes-using-poedit

Does GD Security Headers plugin works with WordPress MultiSite installations?

Yes. Plugin must be activated as Network Wide.

Can I translate GD Security Headers plugin to my language?

All Dev4Press free and lite plugins can be translated via WordPress.org and their translation services. Each plugin on WordPress.org has support for translation, and you can get to it through the plugin Developer panel. To translate plugins on WordPress.org, you need a WordPress.org account. But, if you want to handle translations on your own, each plugin has a POT file with the list of all translation strings