Option Picker is an app that enable merchants create and customize options for their customers to choose before checkout. It allows customers make their extra choices at checkout page. Merchants can also use Option Picker as survey form.
Install Option Picker:
Step 1: Go to Admin > Apps > Featured Apps > Search for Option Picker
Step 2: Click to install the app
Step 3: Customize and name the label + option > Click "save setting"
Step 4: You may test and see it on your checkout page.