This video (episode 3 of 4) adds logic in the Kotlin file to listen for changes in the base amount (EditText) or tip percent (SeekBar), and update the calculation. Since there's no "submit" button in our app, we want to update the UI every time the user makes a change in either of the input fields. ➤ Download Tippy on Google Play: https://play.google.com/store/apps/details?id=com.rkpandey.tipcalculator ➤ Learn Kotlin in 12 Minutes: https://www.youtube.com/watch?v=iYrgWO2oibY ➤ Working with the EditText (adding a text watcher): https://guides.codepath.com/android/Working-with-the-EditText In this series, we build an Android tip calculator app! After you enter a base amount and a tip percentage, the app will calculate the tip and total for you. We also implement a tip percentage animation and a footer to make our app more unique. Playlist:    • Tip Calculator - Build Your First And...   Hi! I’m Rahul, a software engineer with a passion for teaching. I went to Stanford, was a founding engineer at a startup, and have worked at various companies across Silicon Valley. I’m currently an Android Developer at Facebook and teach an Android class at Stanford. Would love to connect with you! This channel is about tech (especially Silicon Valley), combining tactical how-to guides with interviews. 📹 YouTube: null 📝 LinkedIn: https://www.linkedin.com/in/rpandey1234/ 🐦 Twitter: https://twitter.com/rpandey1234 📸 Instagram: https://www.instagram.com/rpandey1234/ 📂 Github: https://github.com/rpandey1234/