diff --git a/.gitignore b/.gitignore
index e315327..f9e5805 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,5 +1,7 @@
 build/
 source-apk/*.apk
+keystores/*.keystore
 tools/*
 !tools/smali-2.5.2.jar
-!tools/apktool_2.9.3.jar
\ No newline at end of file
+!tools/apktool_2.9.3.jar
+!tools/apksigner.jar
diff --git a/build.py b/build.py
index a1897ca..b0e87e6 100644
--- a/build.py
+++ b/build.py
@@ -120,13 +120,51 @@ class Task:
         debugFlag = ('-d',) if ('d' in ''.join(sys.argv[2:])) else ()
 
         print("Building apk...")
-        subprocess.run(['java', '-jar', './tools/apktool_2.9.3.jar', 'b', *debugFlag, 'build/merged', '-o', 'build/apk/tumblr-ykit.apk'])
+        subprocess.run(['java', '-jar', './tools/apktool_2.9.3.jar', 'b', *debugFlag, 'build/merged', '-o', 'build/apk/tumblr-ykit-unsigned.apk'])
+
+    def alignApk():
+        Task.buildApk()
+
+        print('Aligning apk...')
+        subprocess.run(['tools/zipalign', '-p', '-f', '-v', '4', 'build/apk/tumblr-ykit-unsigned.apk', 'build/apk/tumblr-ykit.apk'])
+
+    def debugKey():
+        if Path('keystores/debug.keystore').exists():
+            return
+
+        print("Debug keystore does not exist, generating...")
+        subprocess.run(['keytool', '-genkey', '-v', '-keystore', 'keystores/debug.keystore', '-alias', 'alias_name', '-keyalg', 'RSA', '-keysize', '2048', '-validity', '10000', '-storepass', '123456', '-keypass', '123456', '-dname', 'CN=, OU=, O=, L=, ST=, C='])
+
+    def signApk():
+        Task.alignApk()
+        Task.debugKey()
+
+        debugFlag = 'd' in ''.join(sys.argv[2:])
+        releaseFlag = 'r' in ''.join(sys.argv[2:])
+
+        if not (debugFlag or releaseFlag):
+            print("Neither debug nor release flag was specified so the apk will not be signed.")
+            return
+
+        if releaseFlag:
+            if not Path('keystores/release.keystore').exists():
+                print("release.keystore is missing from keystores directory")
+                return
+            
+            keystoreOpts = ('--ks', 'keystores/release.keystore',)
+        else:
+            Task.debugKey()
+            keystoreOpts = ('--ks', 'keystores/debug.keystore', '--ks-pass', 'pass:123456',)
+
+        print('Signing apk...')
+        subprocess.run(['java', '-jar', './tools/apksigner.jar', 'sign', *keystoreOpts, 'build/apk/tumblr-ykit.apk'])
+        print("Successfully signed apk in 'build/apk/tumblr-ykit.apk' using " + ('release' if releaseFlag else 'debug') + ' keystore')
 
     def deployToAndroidStudio():
         projDir = Path.home() / 'ApkProjects/tumblr-ykit'
         if not projDir.exists():
             print("No project named 'tumblr-ykit' in ~/ApkProjects/")
-        
+
         shutil.copy('build/apk/tumblr-ykit.apk', projDir / 'tumblr-ykit.apk')
         print("Deployed to Android Studio")
 
@@ -137,9 +175,11 @@ def main():
             Task.clean()
         case 'extract':
             Task.extractApk()
-        case 'build':
+        case 'assemble':
             Task.buildApk()
-
+        case 'build':
+            Task.signApk()
+            
             if ('a' in ''.join(sys.argv[2:])):
                 Task.deployToAndroidStudio()
 
diff --git a/keystores/Place_Keystores_Here b/keystores/Place_Keystores_Here
new file mode 100644
index 0000000..279c9ea
--- /dev/null
+++ b/keystores/Place_Keystores_Here
@@ -0,0 +1 @@
+Release keystore must be named 'release.keystore'
\ No newline at end of file
diff --git a/source-apk/Place_Tumblr_Apk_Here b/source-apk/Place_Tumblr_Apk_Here
new file mode 100644
index 0000000..e58a135
--- /dev/null
+++ b/source-apk/Place_Tumblr_Apk_Here
@@ -0,0 +1 @@
+Place tumblr apk version
\ No newline at end of file
diff --git a/tools/apksigner.jar b/tools/apksigner.jar
new file mode 100644
index 0000000..f4adcff
Binary files /dev/null and b/tools/apksigner.jar differ