Word 2016 and Word 2013 allow users to add apps to the document using the options available as part of the Apps for Office. For example if you want to have the sticky notes functionality in your word document then you add the Sticky Notes App.
Adding Sticky Notes to My Apps
The first step to insert app in Word document is to make sure that the app is available as part your My Apps in Office Store
Step 1: Login to your Office Store Account.
Step 2: You can either use the Search Text box to locate the App or by clicking the Apps for Office and SharePoint.
Step 3: Now select Sticky Notes for Office from the list and click Add button.
The My Apps section in Office should display the newly added app.
Adding app to Word document
Step 1: Launch the Word document where you want to insert the app.
Step 2: Click the Apps for Office option under Insert menu.
Step 3: The Apps for Office window will display the Sticky Notes for Office app.
Select the App and click the Insert Button. The Sticky Notes App will now appear on the right hand side of your Word document.