diff --git a/README.md b/README.md
index a3fd959..f5ddfb1 100644
--- a/README.md
+++ b/README.md
@@ -7,14 +7,45 @@
 
 ## Usage
 
+### Application
+
 ```go
 package main
 
 import (
 	"context"
 	"fmt"
-	"github.com/mattn/go-mastodon"
 	"log"
+
+	"github.com/mattn/go-mastodon"
+)
+
+func main() {
+	app, err := mastodon.RegisterApp(context.Background(), &mastodon.AppConfig{
+		Server:     "https://mstdn.jp",
+		ClientName: "client-name",
+		Scopes:     "read write follow",
+		Website:    "https://github.com/mattn/go-mastodon",
+	})
+	if err != nil {
+		log.Fatal(err)
+	}
+	fmt.Printf("client-id    : %s\n", app.ClientID)
+	fmt.Printf("client-secret: %s\n", app.ClientSecret)
+}
+```
+
+### Client
+
+```go
+package main
+
+import (
+	"context"
+	"fmt"
+	"log"
+
+	"github.com/mattn/go-mastodon"
 )
 
 func main() {
@@ -36,6 +67,7 @@ func main() {
 	}
 }
 ```
+
 ## Status of implementations
 
 * [x] GET /api/v1/accounts/:id
diff --git a/cmd/mstdn/README.md b/cmd/mstdn/README.md
index 5e3b917..6b2dd22 100644
--- a/cmd/mstdn/README.md
+++ b/cmd/mstdn/README.md
@@ -10,19 +10,30 @@ NAME:
 
 USAGE:
    mstdn [global options] command [command options] [arguments...]
-   
+
 VERSION:
    0.0.1
-   
+
 COMMANDS:
-     toot      post toot
-     stream    stream statuses
-     timeline  show timeline
-     help, h   Shows a list of commands or help for one command
+     toot          post toot
+     stream        stream statuses
+     timeline      show timeline
+     notification  show notification
+     instance      show instance information
+     account       show account information
+     search        search content
+     follow        follow account
+     followers     show followers
+     upload        upload file
+     delete        delete status
+     init          initialize profile
+     mikami        search mikami
+     help, h       Shows a list of commands or help for one command
 
 GLOBAL OPTIONS:
-   --help, -h     show help
-   --version, -v  print the version
+   --profile value  profile name
+   --help, -h       show help
+   --version, -v    print the version
 ```
 
 ## Installation