diff --git a/src/background/index.js b/src/background/index.js
index 8c4eafc..1e4c078 100644
--- a/src/background/index.js
+++ b/src/background/index.js
@@ -6,7 +6,7 @@ import IndicatorComponent from 'background/components/indicator';
 import reducers from 'background/reducers';
 import { createStore, applyMiddleware } from 'redux';
 import promise from 'redux-promise';
-import * as versions from 'shared/versions';
+import * as versions from './shared/versions';
 
 const store = createStore(
   reducers,
diff --git a/src/background/reducers/index.js b/src/background/reducers/index.js
index 78f855c..465f927 100644
--- a/src/background/reducers/index.js
+++ b/src/background/reducers/index.js
@@ -1,17 +1,8 @@
-import settingReducer from './setting';
-import findReducer from './find';
-import tabReducer from './tab';
+import { combineReducers } from 'redux';
+import setting from './setting';
+import find from './find';
+import tab from './tab';
 
-// Make setting reducer instead of re-use
-const defaultState = {
-  setting: settingReducer(undefined, {}),
-  find: findReducer(undefined, {}),
-  tab: tabReducer(undefined, {}),
-};
-
-export default function reducer(state = defaultState, action = {}) {
-  return { ...state,
-    setting: settingReducer(state.setting, action),
-    find: findReducer(state.find, action),
-    tab: tabReducer(state.tab, action), };
-}
+export default combineReducers({
+  setting, find, tab,
+});
diff --git a/src/background/shared/completions/index.js b/src/background/shared/completions/index.js
index d5875fe..9ca13f7 100644
--- a/src/background/shared/completions/index.js
+++ b/src/background/shared/completions/index.js
@@ -1,6 +1,19 @@
+import commandDocs from 'shared/commands/docs';
 import * as tabs from './tabs';
 import * as histories from './histories';
 import * as bookmarks from './bookmarks';
+import * as properties from 'shared/settings/properties';
+
+const completeCommands = (typing) => {
+  let keys = Object.keys(commandDocs);
+  return keys
+    .filter(name => name.startsWith(typing))
+    .map(name => ({
+      caption: name,
+      content: name,
+      url: commandDocs[name],
+    }));
+};
 
 const getSearchCompletions = (command, keywords, searchConfig) => {
   let engineNames = Object.keys(searchConfig.engines);
@@ -74,20 +87,63 @@ const getBufferCompletions = async(command, keywords, excludePinned) => {
   ];
 };
 
-const getCompletions = (line, settings) => {
-  let typedWords = line.trim().split(/ +/);
-  let typing = '';
-  if (!line.endsWith(' ')) {
-    typing = typedWords.pop();
+const getSetCompletions = (command, keywords) => {
+  let keys = Object.keys(properties.docs).filter(
+    name => name.startsWith(keywords)
+  );
+  let items = keys.map((key) => {
+    if (properties.types[key] === 'boolean') {
+      return [
+        {
+          caption: key,
+          content: command + ' ' + key,
+          url: 'Enable ' + properties.docs[key],
+        }, {
+          caption: 'no' + key,
+          content: command + ' no' + key,
+          url: 'Disable ' + properties.docs[key],
+        }
+      ];
+    }
+    return [
+      {
+        caption: key,
+        content: command + ' ' + key,
+        url: 'Set ' + properties.docs[key],
+      }
+    ];
+  });
+  items = items.reduce((acc, val) => acc.concat(val), []);
+  if (items.length === 0) {
+    return Promise.resolve([]);
   }
+  return Promise.resolve([
+    {
+      name: 'Properties',
+      items,
+    }
+  ]);
+};
 
-  if (typedWords.length === 0) {
-    return Promise.resolve([]);
+const complete = (line, settings) => {
+  let trimmed = line.trimStart();
+  let words = trimmed.split(/ +/);
+  let name = words[0];
+  if (words.length === 1) {
+    let items = completeCommands(name);
+    if (items.length === 0) {
+      return Promise.resolve([]);
+    }
+    return Promise.resolve([
+      {
+        name: 'Console Command',
+        items: completeCommands(name),
+      }
+    ]);
   }
-  let name = typedWords.shift();
-  let keywords = typedWords.concat(typing).join(' ');
+  let keywords = trimmed.slice(name.length).trimStart();
 
-  switch (name) {
+  switch (words[0]) {
   case 'o':
   case 'open':
   case 't':
@@ -108,12 +164,10 @@ const getCompletions = (line, settings) => {
   case 'bdelete':
   case 'bdeletes':
     return getBufferCompletions(name, keywords, true);
+  case 'set':
+    return getSetCompletions(name, keywords);
   }
   return Promise.resolve([]);
 };
 
-const complete = (line, settings) => {
-  return getCompletions(line, settings);
-};
-
 export { complete };
diff --git a/src/shared/versions/index.js b/src/background/shared/versions/index.js
similarity index 95%
rename from src/shared/versions/index.js
rename to src/background/shared/versions/index.js
index ba3d183..aa09c92 100644
--- a/src/shared/versions/index.js
+++ b/src/background/shared/versions/index.js
@@ -1,6 +1,6 @@
 import * as storage from './storage';
 import * as releaseNotes from './release-notes';
-import manifest from '../../../manifest.json';
+import manifest from '../../../../manifest.json';
 
 const NOTIFICATION_ID = 'vimvixen-update';
 
diff --git a/src/shared/versions/release-notes.js b/src/background/shared/versions/release-notes.js
similarity index 100%
rename from src/shared/versions/release-notes.js
rename to src/background/shared/versions/release-notes.js
diff --git a/src/shared/versions/storage.js b/src/background/shared/versions/storage.js
similarity index 100%
rename from src/shared/versions/storage.js
rename to src/background/shared/versions/storage.js
diff --git a/src/console/reducers/index.js b/src/console/reducers/index.js
index 71b0776..7dcad17 100644
--- a/src/console/reducers/index.js
+++ b/src/console/reducers/index.js
@@ -11,6 +11,9 @@ const defaultState = {
 };
 
 const nextSelection = (state) => {
+  if (state.completions.length === 0) {
+    return [-1, -1];
+  }
   if (state.groupSelection < 0) {
     return [0, 0];
   }
diff --git a/src/content/reducers/index.js b/src/content/reducers/index.js
index c3a474e..6e6a147 100644
--- a/src/content/reducers/index.js
+++ b/src/content/reducers/index.js
@@ -1,25 +1,10 @@
-import addonReducer from './addon';
-import findReducer from './find';
-import settingReducer from './setting';
-import inputReducer from './input';
-import followControllerReducer from './follow-controller';
+import { combineReducers } from 'redux';
+import addon from './addon';
+import find from './find';
+import setting from './setting';
+import input from './input';
+import followController from './follow-controller';
 
-// Make setting reducer instead of re-use
-const defaultState = {
-  addon: addonReducer(undefined, {}),
-  find: findReducer(undefined, {}),
-  setting: settingReducer(undefined, {}),
-  input: inputReducer(undefined, {}),
-  followController: followControllerReducer(undefined, {}),
-};
-
-export default function reducer(state = defaultState, action = {}) {
-  return {
-    ...state,
-    addon: addonReducer(state.addon, action),
-    find: findReducer(state.find, action),
-    setting: settingReducer(state.setting, action),
-    input: inputReducer(state.input, action),
-    followController: followControllerReducer(state.followController, action),
-  };
-}
+export default combineReducers({
+  addon, find, setting, input, followController,
+});
diff --git a/src/shared/commands/docs.js b/src/shared/commands/docs.js
new file mode 100644
index 0000000..c73eb71
--- /dev/null
+++ b/src/shared/commands/docs.js
@@ -0,0 +1,11 @@
+export default {
+  set: 'Set a value of the property',
+  open: 'Open a URL or search by keywords in current tab',
+  tabopen: 'Open a URL or search by keywords in new tab',
+  winopen: 'Open a URL or search by keywords in new window',
+  buffer: 'Sekect tabs by matched keywords',
+  bdelete: 'Close a certain tab matched by keywords',
+  bdeletes: 'Close all tabs matched by keywords',
+  quit: 'Close the current tab',
+  quitall: 'Close all tabs',
+};
diff --git a/src/shared/settings/properties.js b/src/shared/settings/properties.js
index 4bda8d6..b392cbb 100644
--- a/src/shared/settings/properties.js
+++ b/src/shared/settings/properties.js
@@ -15,4 +15,10 @@ const defaults = {
   adjacenttab: true,
 };
 
-export { types, defaults };
+const docs = {
+  hintchars: 'Hint characters on follow mode',
+  smoothscroll: 'smooth scroll',
+  adjacenttab: 'open adjacent tabs',
+};
+
+export { types, defaults, docs };
diff --git a/test/shared/versions/index.test.js b/test/background/shared/versions/index.test.js
similarity index 91%
rename from test/shared/versions/index.test.js
rename to test/background/shared/versions/index.test.js
index d90f04c..d65dd9a 100644
--- a/test/shared/versions/index.test.js
+++ b/test/background/shared/versions/index.test.js
@@ -1,5 +1,5 @@
-import * as versions from 'shared/versions';
-import manifest from '../../../manifest.json';
+import * as versions from 'background/shared/versions';
+import manifest from '../../../../manifest.json';
 
 describe("shared/versions/storage", () => {
   describe('#checkUpdated', () => {
diff --git a/test/shared/versions/storage.test.js b/test/background/shared/versions/storage.test.js
similarity index 92%
rename from test/shared/versions/storage.test.js
rename to test/background/shared/versions/storage.test.js
index f541abf..f452516 100644
--- a/test/shared/versions/storage.test.js
+++ b/test/background/shared/versions/storage.test.js
@@ -1,4 +1,4 @@
-import * as storage from 'shared/versions/storage';
+import * as storage from 'background/shared/versions/storage';
 
 describe("shared/versions/storage", () => {
   describe('#load', () => {