diff --git a/extension/common.js b/extension/common.js
index aa38379..c0e0ad3 100644
--- a/extension/common.js
+++ b/extension/common.js
@@ -225,6 +225,15 @@ function match({url, tabId}) {
     // if s is an array select a random string
     if (Array.isArray(s)) {
       s = s[Math.floor(Math.random() * s.length)];
+      // set session mode if key is either on _[key] or _['*'] lists
+      if (prefs.custom._ && Array.isArray(prefs.custom._)) {
+        if (prefs.custom._.indexOf(key) !== -1) {
+          prefs.custom[key] = s;
+        }
+        else if (prefs.custom._.indexOf('*') !== -1) {
+          prefs.custom['*'] = s;
+        }
+      }
     }
     if (s) {
       return ua.parse(s);
diff --git a/extension/data/options/index.html b/extension/data/options/index.html
index 2befbd8..a44bee5 100644
--- a/extension/data/options/index.html
+++ b/extension/data/options/index.html
@@ -36,7 +36,7 @@
     </tr>
     <tr>
       <td>
-        <label><input type="radio" name="mode" value="custom" id="mode-custom"> <span class="h">Custom mode</span>: Try to resolve the user-agent string from a JSON object; otherwise either use the default user-agent string or use the one that user is set from the popup. Use "*" as the hostname to match all domains. You can randomly select from multiple user-agent strings by providing an array instead of a string.</label> <a href="#" id="sample">Insert</a> a sample JSON object.
+        <label><input type="radio" name="mode" value="custom" id="mode-custom"> <span class="h">Custom mode</span>: Try to resolve the user-agent string from a JSON object; otherwise either use the default user-agent string or use the one that the user is set from the popup interface. Use "*" as the hostname to match all domains. You can randomly select from multiple user-agent strings by providing an array instead of a fixed string. If there is a "_" key in your JSON object which refers to an array of hostnames, then the extension only randomly selects the user-agent string once for each hostname inside this list. This is useful if you don't want the random user-agent to change until this browser session is over.</label> Press <a href="#" id="sample">here</a> to insert a sample JSON object.
       </td>
     </tr>
     <tr>
@@ -53,9 +53,9 @@
     </tr>
   </table>
   <p>
+    <button id="help">FAQs Page (Help)</button>
     <button id="donate">Support Development</button>
-    <button id="reset">Reset</button>
-    <button id="save">Save</button>
+    <button id="reset">Reset</button> - <button id="save">Save</button>
     <span id="status"></span>
   </p>
 
diff --git a/extension/data/options/index.js b/extension/data/options/index.js
index ba923a9..9838838 100644
--- a/extension/data/options/index.js
+++ b/extension/data/options/index.js
@@ -93,3 +93,9 @@ document.getElementById('reset').addEventListener('click', e => {
     });
   }
 });
+
+document.getElementById('help').addEventListener('click', () => {
+  chrome.tabs.create({
+    url: chrome.runtime.getManifest().homepage_url
+  });
+});