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README.md

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-# Pomodoro
-Chrome Extension <Pomodoro>
+# 🍅 Pomodoro
+Chrome Extension [Pomodoro](https://chrome.google.com/webstore/detail/pomodoro/gilefcgjiehejipngaljmmncadgbmfec)
+
+<br />
+
+## 🪧 Introduction
+Do you know 'Pomodoro Technique'?   
+Please check this [link](https://en.wikipedia.org/wiki/Pomodoro_Technique).   
+
+This extension can do these.
+- Timer (25 and 50 minutes)
+- Notification (You need to allow Chrome Notification.)
+- Remaining time (in real time)
+
+<br />
+
+## 📌 Feature
+- This extension made in `manifest v3`.
+- Only use `popup` action.
+
+<br />
+
+## 🗣 Feedback
+Please comment in google chrome extension.   
+Thank you for your interest. :)