diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..e43b0f9
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1 @@
+.DS_Store
diff --git a/README.md b/README.md
index 6a94544..5028931 100644
--- a/README.md
+++ b/README.md
@@ -11,8 +11,10 @@ DHT implements the bittorrent DHT protocol in Go. Now it includes:
 
 It contains two modes, the standard mode and the crawling mode. The standard
 mode follows the BEPs, and you can use it as a standard dht server. The crawling
-mode aims to spide as more medata info as possiple. It doesn't fllow the
-standard BEPs protocol.
+mode aims to spide as more medata info as possiple. It doesn't follow the
+standard BEPs protocol. With the crawling mode, you can build another Pirate Bay.
+
+[bthub.io](http://bthub.io) is a BT search engine based on the crawling mode.
 
 ## Install
 
diff --git a/doc/.DS_Store b/doc/.DS_Store
new file mode 100644
index 0000000..d99a2fd
Binary files /dev/null and b/doc/.DS_Store differ