diff --git a/CHANGELOG.md b/CHANGELOG.md
index 38efe83..a576e05 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,12 @@
+## 1.2.1
+
+- docs: Fix broken images in README.md
+
+## 1.2.0
+
+- enhance: Simplify get functions
+- docs: Update README.md
+
 ## 1.1.0
 
 - enhance: Early return if response payload is empty
diff --git a/README.md b/README.md
index 717cb3a..5482038 100644
--- a/README.md
+++ b/README.md
@@ -1,7 +1,146 @@
 # Dart Google Sheet Remote Config
 
-This is a Dart package that allows you to use Google Sheets as a remote config for your Dart/Flutter app. It is inspired by @theapache64's [blog](https://theapache64.github.io/posts/google-sheet-as-remote-config-for-microcontrollers/).
+[![pub package](https://img.shields.io/pub/v/dart_gsheet_remote_config.svg)](https://pub.dev/packages/dart_gsheet_remote_config)
 
-## Why Google Sheets?
+This is a package that allows you to use Google Sheets as a remote config for changing your Dart/Flutter app's behaviors, settings,.. without updating. It is inspired by @theapache64's [blog](https://theapache64.github.io/posts/google-sheet-as-remote-config-for-microcontrollers/).
+
+## How it works
+
+- This package uses [Query Visualization API](https://developers.google.com/chart/interactive/docs/querylanguage) and some tricks to get data from Google Sheet.
+
+## MUST READ before use
+
+- If you have some configs (API key, token,...) related to security, please **DO NOT** use this package, because it is **PUBLIC** and **NOT SECURE**.
+
+## Setup
+
+### Google Sheet
+
+- Create a Google Sheet document, make it **PUBLIC** (If not you will get 401, in the future I will find the way to inject auth token for private sheeet) and put an easy to remember document name.
+
+![image](https://github.com/dungngminh/dart_gsheet_remote_config/raw/main/art/image.png)
+
+- Add your data to sheet in format:
+  - First column will be keys
+  - Second column will be values
+
+![image_2](https://github.com/dungngminh/dart_gsheet_remote_config/raw/main/art/image_2.png)
+
+- **MUST READ**: Every values in sheet is marked as **String**. For **int**, **doube**, **bool**, we should convert it to **String**, use `TO_TEXT` fomular to convert value to **String** type:
+
+![image_3](https://github.com/dungngminh/dart_gsheet_remote_config/raw/main/art/image_3.png)
+
+- You can create more than 1 worksheet to manage your config better and it can be selected to get correct data.
+
+![image_4](https://github.com/dungngminh/dart_gsheet_remote_config/raw/main/art/image_4.png)
+
+### Dart
+
+```sh
+dart pub add dart_gsheet_remote_config
+```
+
+### Flutter
+
+```sh
+flutter pub add dart_gsheet_remote_config
+```
 
 ## How to use
+
+Create your `SheetRemoteConfig` instance.
+
+```dart
+import 'package:dart_gsheet_remote_config/dart_gsheet_remote_config.dart';
+
+final remoteConfig = SheetRemoteConfig();
+```
+
+`SheetRemoteConfig` has a param `Client` from `http` package so you can pass your custom `Client` object when create `SheetRemoteConfig` instance.
+
+```dart
+import 'package:dart_gsheet_remote_config/dart_gsheet_remote_config.dart';
+import 'package:http/http.dart' as http;
+
+final client = http.Client();
+
+final remoteConfig = SheetRemoteConfig(client: client);
+```
+
+### Fetch remote config data
+
+`SheetRemoteConfig` provides `initilize` function and you must pass `id` and `sheetName` to initilize remote config:
+
+- Document `id` you can find it in your Google Sheet document Url. For example your Sheet url is `https://docs.google.com/spreadsheets/d/123456789`, `id` will be `123456789`.
+
+- `sheetName` is worksheet name, **nullable**, first worksheet will be used if `null` or passed value is not found.
+
+```dart
+import 'package:dart_gsheet_remote_config/dart_gsheet_remote_config.dart';
+
+final remoteConfig = SheetRemoteConfig();
+
+await remoteConfig.initilize(id: '123456789'); // First worksheet will be used
+
+await remoteConfig.initilize(id: '123456789', sheetName: 'Sheet1'); // Use specific worksheet name
+```
+
+**MUST READ**: `id` mustn't be hardcode if you don't want others to use your remote config. You can use `id` as `.env` field or via `dart-define` and pass it to your app via environment variable. You can use some packages like [`flutter_dotenv`](https://pub.dev/packages/flutter_dotenv), [`envied`](https://pub.dev/packages/envied) to load `.env` file.
+
+### Get data from remote
+
+`SheetRemoteConfig` fetchs data in CSV format, data is returned in key-value format, you can `key` to get `value` via
+get functions, currently `SheetRemoteConfig` supports `String`, `int`, `double`, `bool`.
+
+Example response:
+
+```csv
+"key1","TRUE"
+"key2","10"
+"key3","value from key 3"
+"key4,"1.0"
+```
+
+And get data:
+
+```dart
+final valueKey1 = remoteConfig.getBool('key1');
+print(valueKey1); // true
+
+final valueKey2 = remoteConfig.getInt('key2');
+print(valueKey2); // 10
+
+final valueKey3 = remoteConfig.getString('key3');
+print(valueKey3); // value from key 3
+
+final valueKey4 = remoteConfig.getDouble('key4');
+print(valueKey4); // 1.0
+```
+
+If provided `key` is not found or provided `T` is incorrect, get functions will return `null`.
+
+```dart
+final valueKey5 = remoteConfig.getString('key5');
+print(valueKey5); // null
+```
+
+You can pass `defaultValue` when get functions returns `null`.
+
+```dart
+final valueKey5 = remoteConfig.getString('key5', defaultValue: 'this is default value');
+print(valueKey5); // this is default value
+```
+
+## Get all data from remote
+
+`SheetRemoteConfig` provides `getAll` function to get all data from remote.
+
+```dart
+final allData = remoteConfig.getAll();
+print(allData); // {key1: true, key2: 10, key3: value from key 3, key4: 1.0}
+
+```
+
+## Happy coding
+
+That's all for now! Want a feature? Found a bug? Create an [issue](https://github.com/dungngminh/dart_gsheet_remote_config/issues/new)!
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diff --git a/pubspec.lock b/pubspec.lock
index 2e2c22a..3d0162c 100644
--- a/pubspec.lock
+++ b/pubspec.lock
@@ -5,23 +5,23 @@ packages:
     dependency: transitive
     description:
       name: _fe_analyzer_shared
-      sha256: "16e298750b6d0af7ce8a3ba7c18c69c3785d11b15ec83f6dcd0ad2a0009b3cab"
+      sha256: "45cfa8471b89fb6643fe9bf51bd7931a76b8f5ec2d65de4fb176dba8d4f22c77"
       url: "https://pub.dev"
     source: hosted
-    version: "76.0.0"
+    version: "73.0.0"
   _macros:
     dependency: transitive
     description: dart
     source: sdk
-    version: "0.3.3"
+    version: "0.3.2"
   analyzer:
     dependency: transitive
     description:
       name: analyzer
-      sha256: "1f14db053a8c23e260789e9b0980fa27f2680dd640932cae5e1137cce0e46e1e"
+      sha256: "4959fec185fe70cce007c57e9ab6983101dbe593d2bf8bbfb4453aaec0cf470a"
       url: "https://pub.dev"
     source: hosted
-    version: "6.11.0"
+    version: "6.8.0"
   args:
     dependency: transitive
     description:
@@ -194,10 +194,10 @@ packages:
     dependency: "direct dev"
     description:
       name: lints
-      sha256: "4a16b3f03741e1252fda5de3ce712666d010ba2122f8e912c94f9f7b90e1a4c3"
+      sha256: "976c774dd944a42e83e2467f4cc670daef7eed6295b10b36ae8c85bcbf828235"
       url: "https://pub.dev"
     source: hosted
-    version: "5.1.0"
+    version: "4.0.0"
   logging:
     dependency: transitive
     description:
@@ -210,10 +210,10 @@ packages:
     dependency: transitive
     description:
       name: macros
-      sha256: "1d9e801cd66f7ea3663c45fc708450db1fa57f988142c64289142c9b7ee80656"
+      sha256: "0acaed5d6b7eab89f63350bccd82119e6c602df0f391260d0e32b5e23db79536"
       url: "https://pub.dev"
     source: hosted
-    version: "0.1.3-main.0"
+    version: "0.1.2-main.4"
   matcher:
     dependency: transitive
     description:
diff --git a/pubspec.yaml b/pubspec.yaml
index 2f925b4..5d44590 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -1,6 +1,7 @@
 name: dart_gsheet_remote_config
-description: Remote config for Dart/Flutter and use Google Sheets to do that
-version: 1.1.0
+description: A package that allows you to use Google Sheets as a remote config for changing your Dart/Flutter app's behaviors, settings,.. without updating.
+version: 1.2.1+1
+topics: [remote, config]
 repository: https://github.com/dungngminh/dart_gsheet_remote_config
 issue_tracker: https://github.com/dungngminh/dart_gsheet_remote_config/issues