Merge f570ae3bc950fedf793777c13b36686105b7894c into ee0375473564956609f207f71b1343c83152a6b8

src/background.js

@@ -6,13 +6,20 @@
  * @return {void}           -
  */
 function openInPopup(url, width, height) {
-  browser.windows.create({
+  if(browser.windows) {
-    url,
+    browser.windows.create({
-    type: 'popup',
+      url,
-    allowScriptsToClose: true,
+      type: 'popup',
-    width,
+      allowScriptsToClose: true,
-    height,
+      width,
-  });
+      height,
+    });
+  }else if(browser.tabs){
+    browser.tabs.create({
+      active: true,
+      url: url
+    })
+  }
 }
 
 /**