diff --git a/README.md b/README.md
index 2f0b39d..e21dbaf 100644
--- a/README.md
+++ b/README.md
@@ -6,7 +6,7 @@
 
 ## 🎯 功能概述
 
-SpriteTool 是一個整合式的 Web 應用程式，集合了三個專業級工具於一身：
+SpriteTool 是一個整合式的 Web 應用程式，集合了四個專業級工具於一身：
 
 ### 📏 Grid Tool（網格工具）
 用於在圖片上定義規則的網格區域並進行批量選取。
@@ -55,6 +55,20 @@ SpriteTool 是一個整合式的 Web 應用程式，集合了三個專業級工
 
 ---
 
+### 🔄 Sprite Flipper（精靈翻轉工具）
+快速對 Sprite Sheet 中的每個動作格進行水平翻轉（左右鏡像）。
+
+**功能特性：**
+- 根據設定的行列數精確分割格子
+- 批量水平翻轉所有 Cell
+- 支援即時原圖與結果預覽
+- 保持 Alpha 透明頻道
+- 一鍵下載翻轉後的完整 Sprite Sheet
+
+**使用場景：** 動畫鏡像製作、Tilemap 對稱變體生成、角色動作調整
+
+---
+
 ## 🚀 快速開始
 
 ### 環境需求
@@ -83,6 +97,7 @@ python tool.py
 - **Grid Tool**: `http://localhost:8000/grid/`
 - **Sprite Picker**: `http://localhost:8000/picker/`
 - **Shiny Maker**: `http://localhost:8000/shiny/`
+- **Sprite Flipper**: `http://localhost:8000/flipper/`
 
 ---
 
@@ -94,6 +109,8 @@ SpriteTool/
 ├── sprite_tool_fullstack.py         # Grid Tool 子應用
 ├── sprite_webtool.py                # Sprite Picker 子應用
 ├── shiny_maker.py                   # Shiny Monster Maker 子應用
+├── rotate_webtool.py                # Sprite Flipper 子應用
+├── rotate.py                        # Flipper 核心處理邏輯
 ├── output/                          # Grid Tool 導出目錄
 ├── shiny_output/                    # Shiny Maker 導出目錄
 └── README.md                        # 本文件
@@ -135,6 +152,14 @@ SpriteTool/
 3. **實時預覽** - 右側即時顯示效果
 4. **下載** - 滿意後點擊「下載」按鈕
 
+### Sprite Flipper 工作流
+
+1. **上傳圖片** - 選擇要翻轉的 Sprite Sheet
+2. **設定分割** - 輸入圖片對應的行列數（Cols/Rows）
+3. **執行翻轉** - 點擊執行按鈕，系統將自動處理每個格子
+4. **檢查結果** - 下方會顯示翻轉後的預覽圖
+5. **下載** - 點擊下載按鈕取得成品
+
 ---
 
 ## 🛠️ 技術架構
@@ -175,6 +200,10 @@ SpriteTool/
 - `POST /shiny/process` - 處理色違調整
 - `GET /shiny/download` - 下載成品
 
+### Sprite Flipper
+- `GET /flipper/` - 首頁
+- `POST /flipper/flip` - 執行精靈翻轉處理
+
 ---
 
 ## 🎨 UI/UX 特性
@@ -234,5 +263,5 @@ SpriteTool/
 
 ---
 
-**最後更新**: 2026 年 4 月  
-**版本**: 1.0.0
+**最後更新**: 2026 年 5 月  
+**版本**: 1.1.0
diff --git a/README_EN.md b/README_EN.md
index b493cbb..4692288 100644
--- a/README_EN.md
+++ b/README_EN.md
@@ -4,7 +4,7 @@ A powerful suite of game development tools providing a complete solution for Spr
 
 ## 🎯 Feature Overview
 
-SpriteTool is an integrated web application that combines three professional-grade tools into one:
+SpriteTool is an integrated web application that combines four professional-grade tools into one:
 
 ### 📏 Grid Tool
 Used to define regular grid areas on an image and perform batch selections.
@@ -53,6 +53,20 @@ Professional-grade "shiny" variant adjustment using HSV color space.
 
 ---
 
+### 🔄 Sprite Flipper
+Quickly perform horizontal flipping (mirroring) for each animation cell in a Sprite Sheet.
+
+**Key Features:**
+- Precisely split cells based on configured row and column counts.
+- Batch horizontal flip for all cells.
+- Real-time preview of both original and result images.
+- Preserves Alpha transparency channel.
+- One-click download of the complete flipped Sprite Sheet.
+
+**Use Cases:** Creating mirrored animations, symmetrical Tilemap variants, character action adjustments.
+
+---
+
 ## 🚀 Quick Start
 
 ### Prerequisites
@@ -81,6 +95,7 @@ Visit the home page to see all available tools, or access them directly:
 - **Grid Tool**: `http://localhost:8000/grid/`
 - **Sprite Picker**: `http://localhost:8000/picker/`
 - **Shiny Maker**: `http://localhost:8000/shiny/`
+- **Sprite Flipper**: `http://localhost:8000/flipper/`
 
 ---
 
@@ -92,6 +107,8 @@ SpriteTool/
 ├── sprite_tool_fullstack.py         # Grid Tool sub-app
 ├── sprite_webtool.py                # Sprite Picker sub-app
 ├── shiny_maker.py                   # Shiny Monster Maker sub-app
+├── rotate_webtool.py                # Sprite Flipper sub-app
+├── rotate.py                        # Flipper core processing logic
 ├── output/                          # Grid Tool export directory
 ├── shiny_output/                    # Shiny Maker export directory
 └── README.md                        # This file
@@ -133,6 +150,14 @@ SpriteTool/
 3. **Real-time Preview** - View the effect instantly on the right.
 4. **Download** - Click "Download" once satisfied.
 
+### Sprite Flipper Workflow
+
+1. **Upload Image** - Select the Sprite Sheet to flip.
+2. **Set Partition** - Enter the row and column counts (Cols/Rows).
+3. **Execute Flip** - Click the button to process each cell automatically.
+4. **Check Result** - View the flipped preview image below.
+5. **Download** - Click the download button to get the result.
+
 ---
 
 ## 🛠️ Technical Architecture
@@ -173,6 +198,10 @@ SpriteTool/
 - `POST /shiny/process` - Process shiny adjustment.
 - `GET /shiny/download` - Download result.
 
+### Sprite Flipper
+- `GET /flipper/` - Home page.
+- `POST /flipper/flip` - Execute sprite flipping process.
+
 ---
 
 ## 🎨 UI/UX Features
@@ -232,5 +261,5 @@ Issues and Pull Requests are welcome!
 
 ---
 
-**Last Updated**: April 2026  
-**Version**: 1.0.0
+**Last Updated**: May 2026  
+**Version**: 1.1.0