A free app for Android, by Sesame Workshop.

This free app gives children a fun and safe way to talk to their favorite character, Cookie Monster. With this, kids can learn to do basic things like: 

• Form a good habit of taking your vitamins.
• Learn to be safe and respectful of other people.
• Learn to deal with stressful situations.
• Ring a telephone to call a friend or to ask for help.
• Tell the time, and more!

Cookie Monster is a character that children can learn to talk to. He is a friendly blue monster that loves to eat cookies. 

The app uses voice messages and video calls to make the experience more immersive. 

The app is intended for children aged 3 and up.