diff --git a/android/README.md b/android/README.md
index 80996ff..2a2ae9e 100644
--- a/android/README.md
+++ b/android/README.md
@@ -20,8 +20,18 @@ dependencies {
 
 ```kotlin
 import io.github.wulkanowy.signer.android.signContent
+import io.github.wulkanowy.signer.android.getPrivateKeyFromCert
 
+// sign content using PFX certificate and API password
 val signed = signContent(password, certificate, content)
+
+// sign content using private key extracted from PFX
+val signed = signContent(key, content)
+
+// extract private key from PFX
+// using a once generated private key is about 250x faster
+// than using the PFX each time
+val privateKey = getPrivateKeyFromCert(password, certificate)
 ```
 
 ## Tests