smart-follow

javascript:
var cUL = 0;
var pUL = 0;
var fSL = 0;
var hostname = location.hostname;
var uL = 0;
var username = "";
var followURL = "";

try {
   var columnUsername = document.getElementsByClassName("account__header__username")[0].innerHTML;
   var cUL = columnUsername.match(/@/g || []).length;
} catch (err) {}
try {
   var profileUsername = document.getElementsByClassName('public-account-header__tabs__name')[0].innerText;
   var pUL = profileUsername.match(/@/g || []).length;
} catch (err) {}
try {
   if (profileUsername == null) {var profileUsername = document.getElementsByClassName('name')[0].innerText;
   var pUL = profileUsername.match(/@/g || []).length;
   }
} catch (err) {}
try {
   var fullSelection = window.getSelection().toString();
   var fSL = fullSelection.match(/@/g || []).length;
} catch (err) {}

if (fSL) {
   username = fullSelection;
   username = username.trim();
   if (!(username.match(/^@/))) {username='@'+username;}
   username = username.match(/(@)(\S[^\n]+)/)[2];
} else if (cUL) {
   username = columnUsername.match(/(@)(\S[^\n]+)/)[2];
} else if (pUL) {
   username = profileUsername.match(/\n(@)(\S[^\n]+)/)[2];
}
username = username.trim();
hostname = hostname.trim();

if (username) {
	if (username.match(/@/g)) {
    	followURL='https://example.mastodon.instance/authorize_follow?acct='+encodeURIComponent(username);
	} else {
		followURL='https://example.mastodon.instance/authorize_follow?acct='+encodeURIComponent(username+'@'+hostname);
	}    
    void(window.open(followURL, '_blank','width=600,height=600,toolbar=no'));
}