diff --git a/.gitignore b/.gitignore
index 2f6879f..3badb0d 100644
--- a/.gitignore
+++ b/.gitignore
@@ -11,7 +11,7 @@ syntax: glob
 *.db
 *.log
 public/*
-go-selfupdate
+go-selfupdate/go-selfupdate
 example/example-server
 example/hello-updater
 example/public/*
diff --git a/cmd/go-selfupdate/main.go b/cmd/go-selfupdate/main.go
new file mode 100644
index 0000000..08e33f7
--- /dev/null
+++ b/cmd/go-selfupdate/main.go
@@ -0,0 +1,183 @@
+package main
+
+import (
+	"bytes"
+	"compress/gzip"
+	"crypto/sha256"
+	"encoding/json"
+	"flag"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"runtime"
+
+	"github.com/kr/binarydist"
+)
+
+var version, genDir string
+
+type current struct {
+	Version string
+	Sha256  []byte
+}
+
+func generateSha256(path string) []byte {
+	h := sha256.New()
+	b, err := ioutil.ReadFile(path)
+	if err != nil {
+		fmt.Println(err)
+	}
+	h.Write(b)
+	sum := h.Sum(nil)
+	return sum
+	//return base64.URLEncoding.EncodeToString(sum)
+}
+
+type gzReader struct {
+	z, r io.ReadCloser
+}
+
+func (g *gzReader) Read(p []byte) (int, error) {
+	return g.z.Read(p)
+}
+
+func (g *gzReader) Close() error {
+	g.z.Close()
+	return g.r.Close()
+}
+
+func newGzReader(r io.ReadCloser) io.ReadCloser {
+	var err error
+	g := new(gzReader)
+	g.r = r
+	g.z, err = gzip.NewReader(r)
+	if err != nil {
+		panic(err)
+	}
+	return g
+}
+
+func createUpdate(path string, platform string) {
+	c := current{Version: version, Sha256: generateSha256(path)}
+
+	b, err := json.MarshalIndent(c, "", "    ")
+	if err != nil {
+		fmt.Println("error:", err)
+	}
+	err = ioutil.WriteFile(filepath.Join(genDir, platform+".json"), b, 0755)
+	if err != nil {
+		panic(err)
+	}
+
+	os.MkdirAll(filepath.Join(genDir, version), 0755)
+
+	var buf bytes.Buffer
+	w := gzip.NewWriter(&buf)
+	f, err := ioutil.ReadFile(path)
+	if err != nil {
+		panic(err)
+	}
+	w.Write(f)
+	w.Close() // You must close this first to flush the bytes to the buffer.
+	err = ioutil.WriteFile(filepath.Join(genDir, version, platform+".gz"), buf.Bytes(), 0755)
+
+	files, err := ioutil.ReadDir(genDir)
+	if err != nil {
+		fmt.Println(err)
+	}
+
+	for _, file := range files {
+		if file.IsDir() == false {
+			continue
+		}
+		if file.Name() == version {
+			continue
+		}
+
+		os.Mkdir(filepath.Join(genDir, file.Name(), version), 0755)
+
+		fName := filepath.Join(genDir, file.Name(), platform+".gz")
+		old, err := os.Open(fName)
+		if err != nil {
+			// Don't have an old release for this os/arch, continue on
+			continue
+		}
+
+		fName = filepath.Join(genDir, version, platform+".gz")
+		newF, err := os.Open(fName)
+		if err != nil {
+			fmt.Fprintf(os.Stderr, "Can't open %s: error: %s\n", fName, err)
+			os.Exit(1)
+		}
+
+		ar := newGzReader(old)
+		defer ar.Close()
+		br := newGzReader(newF)
+		defer br.Close()
+		patch := new(bytes.Buffer)
+		if err := binarydist.Diff(ar, br, patch); err != nil {
+			panic(err)
+		}
+		ioutil.WriteFile(filepath.Join(genDir, file.Name(), version, platform), patch.Bytes(), 0755)
+	}
+}
+
+func printUsage() {
+	fmt.Println("")
+	fmt.Println("Positional arguments:")
+	fmt.Println("\tSingle platform: go-selfupdate myapp 1.2")
+	fmt.Println("\tCross platform: go-selfupdate /tmp/mybinares/ 1.2")
+}
+
+func createBuildDir() {
+	os.MkdirAll(genDir, 0755)
+}
+
+func main() {
+	outputDirFlag := flag.String("o", "public", "Output directory for writing updates")
+
+	var defaultPlatform string
+	goos := os.Getenv("GOOS")
+	goarch := os.Getenv("GOARCH")
+	if goos != "" && goarch != "" {
+		defaultPlatform = goos + "-" + goarch
+	} else {
+		defaultPlatform = runtime.GOOS + "-" + runtime.GOARCH
+	}
+	platformFlag := flag.String("platform", defaultPlatform,
+		"Target platform in the form OS-ARCH. Defaults to running os/arch or the combination of the environment variables GOOS and GOARCH if both are set.")
+
+	flag.Parse()
+	if flag.NArg() < 2 {
+		flag.Usage()
+		printUsage()
+		os.Exit(0)
+	}
+
+	platform := *platformFlag
+	appPath := flag.Arg(0)
+	version = flag.Arg(1)
+	genDir = *outputDirFlag
+
+	createBuildDir()
+
+	// If dir is given create update for each file
+	fi, err := os.Stat(appPath)
+	if err != nil {
+		panic(err)
+	}
+
+	if fi.IsDir() {
+		files, err := ioutil.ReadDir(appPath)
+		if err == nil {
+			for _, file := range files {
+				createUpdate(filepath.Join(appPath, file.Name()), file.Name())
+			}
+			os.Exit(0)
+		}
+	}
+
+	createUpdate(appPath, platform)
+}
diff --git a/cmd/go-selfupdate/main_test.go b/cmd/go-selfupdate/main_test.go
new file mode 100644
index 0000000..90233d9
--- /dev/null
+++ b/cmd/go-selfupdate/main_test.go
@@ -0,0 +1,6 @@
+package main
+
+import "testing"
+
+func TestUpdater(t *testing.T) {
+}