Website: forms.google.com
Difficulty: Easy
Platform: Available on any device that supports Google Drive
Price: Free
Difficulty: Moderate
Platform: Web, Android & IOS (the app is called GradeCam GO!)
Price: Free for limited features; $15 a month for premium features; see pricing plans
Difficulty: Moderate
Platform: Android & IOS
Price: Free
Difficulty: Moderate
Platform: Web, Android, IOS, Chrome Extension, and has an add-on for PowerPoint & Keynote
Price: Educator Plan is free for up to 40 responses per poll. More features are available on paid plans.