on the the pub.dev page for https://pub.dev/packages/social_share_plugin for the homepage link you link to https://romatroskin.github.io/ - This is not what is expected.
When I click that link I had to find a link to the this github repo and then search through a bunch of forked repos to find this. Please be a nice citizen and fix that would you?
Your documentation is better than some others, which is a start, but if (say) Facebook is not installed why do you take the user to the app/play store? The user doesn't have FB installed because they don't want it on their device. Open the Dialog to show the web share option.