diff --git a/UI/Common/English.lproj/Localizable.strings b/UI/Common/English.lproj/Localizable.strings
index 117952d1b..8da485e51 100644
--- a/UI/Common/English.lproj/Localizable.strings
+++ b/UI/Common/English.lproj/Localizable.strings
@@ -41,6 +41,8 @@
      = "Potentially anyone on the Internet will be able to access your address book \"%{0}\", even if they do not have an account on this system. Is this information suitable for the public Internet?";
 "Give Access" = "Give Access";
 "Keep Private" = "Keep Private";
+"Expand" = "Expand";
+"Reduce" = "Reduce";
 
 /* generic.js */
 "Unable to subscribe to that folder!"
diff --git a/UI/Templates/ContactsUI/UIxContactEditorTemplate.wox b/UI/Templates/ContactsUI/UIxContactEditorTemplate.wox
index d170d9514..d96e9037b 100644
--- a/UI/Templates/ContactsUI/UIxContactEditorTemplate.wox
+++ b/UI/Templates/ContactsUI/UIxContactEditorTemplate.wox
@@ -13,6 +13,8 @@
             <md-button ng-click="toggleCenter()"
                        class="sg-icon-button md-primary md-hue-1 hide show-gt-xs"
                        aria-hidden="true">
+              <md-tooltip ng-if="centerIsClose" md-direction="bottom">{{ ::'Reduce' | loc }}</md-tooltip>
+              <md-tooltip ng-else="centerIsClose" md-direction="bottom">{{ ::'Expand' | loc }}</md-tooltip>
               <md-icon>{{ centerIsClose ? 'fullscreen_exit' : 'fullscreen' }}</md-icon>
             </md-button>
           <md-icon class="material-icons sg-icon-toolbar-bg">contacts</md-icon>
diff --git a/UI/Templates/ContactsUI/UIxContactViewTemplate.wox b/UI/Templates/ContactsUI/UIxContactViewTemplate.wox
index 8b0e7eea7..ee93253ca 100644
--- a/UI/Templates/ContactsUI/UIxContactViewTemplate.wox
+++ b/UI/Templates/ContactsUI/UIxContactViewTemplate.wox
@@ -13,6 +13,8 @@
           <md-button ng-click="toggleCenter()"
                      class="sg-icon-button md-primary md-hue-1 hide show-gt-xs"
                      aria-hidden="true">
+            <md-tooltip ng-if="centerIsClose" md-direction="bottom">{{ ::'Reduce' | loc }}</md-tooltip>
+            <md-tooltip ng-else="centerIsClose" md-direction="bottom">{{ ::'Expand' | loc }}</md-tooltip>
             <md-icon>{{ centerIsClose ? 'fullscreen_exit' : 'fullscreen' }}</md-icon>
           </md-button>
           <md-button class="sg-icon-button hide-gt-xs"
diff --git a/UI/Templates/MailerUI/UIxMailEditor.wox b/UI/Templates/MailerUI/UIxMailEditor.wox
index 7c36b1546..5884afe22 100644
--- a/UI/Templates/MailerUI/UIxMailEditor.wox
+++ b/UI/Templates/MailerUI/UIxMailEditor.wox
@@ -22,6 +22,8 @@
                      class="md-icon-button hide show-gt-xs"
                      aria-hidden="true"
                      ng-if="!isPopup">
+            <md-tooltip ng-if="centerIsClose" md-direction="bottom">{{ ::'Reduce' | loc }}</md-tooltip>
+            <md-tooltip ng-else="centerIsClose" md-direction="bottom">{{ ::'Expand' | loc }}</md-tooltip>
             <md-icon>{{ editor.isFullscreen ? 'fullscreen_exit' : 'fullscreen' }}</md-icon>
           </md-button>
           <!-- from -->
diff --git a/UI/Templates/MailerUI/UIxMailViewTemplate.wox b/UI/Templates/MailerUI/UIxMailViewTemplate.wox
index 7d93e1299..5d69b0ba3 100644
--- a/UI/Templates/MailerUI/UIxMailViewTemplate.wox
+++ b/UI/Templates/MailerUI/UIxMailViewTemplate.wox
@@ -15,6 +15,8 @@
                      class="md-icon-button md-primary md-hue-1 hide show-gt-xs"
                      aria-hidden="true"
                      ng-if="::!isPopup">
+            <md-tooltip ng-if="centerIsClose" md-direction="bottom">{{ ::'Reduce' | loc }}</md-tooltip>
+            <md-tooltip ng-else="centerIsClose" md-direction="bottom">{{ ::'Expand' | loc }}</md-tooltip>
             <md-icon>{{ centerIsClose ? 'fullscreen_exit' : 'fullscreen' }}</md-icon>
           </md-button>
           <md-button class="md-icon-button"
diff --git a/UI/Templates/SchedulerUI/UIxCalDayView.wox b/UI/Templates/SchedulerUI/UIxCalDayView.wox
index d7ba52307..9df3c8cdb 100644
--- a/UI/Templates/SchedulerUI/UIxCalDayView.wox
+++ b/UI/Templates/SchedulerUI/UIxCalDayView.wox
@@ -12,6 +12,8 @@
       <md-button ng-click="toggleCenter({save: true})"
                  class="md-icon-button md-primary md-hue-1 hide show-gt-xs"
                  aria-hidden="true">
+        <md-tooltip ng-if="centerIsClose" md-direction="bottom">{{ ::'Reduce' | loc }}</md-tooltip>
+        <md-tooltip ng-else="centerIsClose" md-direction="bottom">{{ ::'Expand' | loc }}</md-tooltip>
         <md-icon>{{ centerIsClose ? 'fullscreen_exit' : 'fullscreen' }}</md-icon>
       </md-button>
       <md-button class="sg-icon-button"
diff --git a/UI/Templates/SchedulerUI/UIxCalMonthView.wox b/UI/Templates/SchedulerUI/UIxCalMonthView.wox
index ee8aaed5e..bf985d735 100644
--- a/UI/Templates/SchedulerUI/UIxCalMonthView.wox
+++ b/UI/Templates/SchedulerUI/UIxCalMonthView.wox
@@ -12,6 +12,8 @@
       <md-button ng-click="toggleCenter({save: true})"
                  class="md-icon-button md-primary md-hue-1 hide show-gt-xs"
                  aria-hidden="true">
+        <md-tooltip ng-if="centerIsClose" md-direction="bottom">{{ ::'Reduce' | loc }}</md-tooltip>
+        <md-tooltip ng-else="centerIsClose" md-direction="bottom">{{ ::'Expand' | loc }}</md-tooltip>
         <md-icon>{{ centerIsClose ? 'fullscreen_exit' : 'fullscreen' }}</md-icon>
       </md-button>
       <md-button class="md-icon-button"
diff --git a/UI/Templates/SchedulerUI/UIxCalMulticolumnDayView.wox b/UI/Templates/SchedulerUI/UIxCalMulticolumnDayView.wox
index f487aa820..2ebf0d205 100644
--- a/UI/Templates/SchedulerUI/UIxCalMulticolumnDayView.wox
+++ b/UI/Templates/SchedulerUI/UIxCalMulticolumnDayView.wox
@@ -12,6 +12,8 @@
       <md-button ng-click="toggleCenter({save: true})"
                  class="md-icon-button md-primary md-hue-1 hide show-gt-xs"
                  aria-hidden="true">
+        <md-tooltip ng-if="centerIsClose" md-direction="bottom">{{ ::'Reduce' | loc }}</md-tooltip>
+        <md-tooltip ng-else="centerIsClose" md-direction="bottom">{{ ::'Expand' | loc }}</md-tooltip>
         <md-icon>{{ centerIsClose ? 'fullscreen_exit' : 'fullscreen' }}</md-icon>
       </md-button>
       <md-button class="md-icon-button"
diff --git a/UI/Templates/SchedulerUI/UIxCalWeekView.wox b/UI/Templates/SchedulerUI/UIxCalWeekView.wox
index fb4078eb6..dacb2d571 100644
--- a/UI/Templates/SchedulerUI/UIxCalWeekView.wox
+++ b/UI/Templates/SchedulerUI/UIxCalWeekView.wox
@@ -12,6 +12,8 @@
       <md-button ng-click="toggleCenter({save: true})"
                  class="md-icon-button md-primary md-hue-1 hide show-gt-xs"
                  aria-hidden="true">
+        <md-tooltip ng-if="centerIsClose" md-direction="bottom">{{ ::'Reduce' | loc }}</md-tooltip>
+        <md-tooltip ng-else="centerIsClose" md-direction="bottom">{{ ::'Expand' | loc }}</md-tooltip>
         <md-icon>{{ centerIsClose ? 'fullscreen_exit' : 'fullscreen' }}</md-icon>
       </md-button>
       <md-button class="md-icon-button"
diff --git a/UI/Templates/UIxTopnavToolbar.wox b/UI/Templates/UIxTopnavToolbar.wox
index eca299ba4..16250b261 100644
--- a/UI/Templates/UIxTopnavToolbar.wox
+++ b/UI/Templates/UIxTopnavToolbar.wox
@@ -9,6 +9,8 @@
     <md-button ng-click="toggleLeft()"
                class="md-icon-button hide show-gt-md"
                label:aria-label="Toggle Menu">
+      <md-tooltip ng-if="leftIsClose" md-direction="bottom">{{ ::'Reduce' | loc }}</md-tooltip>
+      <md-tooltip ng-else="leftIsClose" md-direction="bottom">{{ ::'Expand' | loc }}</md-tooltip>
       <md-icon>{{ leftIsClose ? 'fullscreen_exit' : 'fullscreen' }}</md-icon>
     </md-button>
     <md-button ng-click="toggleLeft()"