diff --git a/build.sh b/build.sh
index 7866304..76f7802 100755
--- a/build.sh
+++ b/build.sh
@@ -257,9 +257,31 @@ build_release() {
     fi
 }
 
-# Placeholder functions — implemented in subsequent tasks
-build_debug()      { warn "Not yet implemented"; }
-clean_build()      { warn "Not yet implemented"; }
+build_debug() {
+    info "Building debug APK..."
+    echo ""
+
+    if ./gradlew assembleDebug; then
+        copy_apk "debug"
+    else
+        echo ""
+        error "Build failed. Check the output above for details."
+        return 1
+    fi
+}
+
+clean_build() {
+    info "Cleaning build artifacts..."
+
+    ./gradlew clean 2>/dev/null
+
+    if [[ -d "$DIST_DIR" ]]; then
+        rm -rf "$DIST_DIR"
+        success "Removed $DIST_DIR/"
+    fi
+
+    success "Clean complete."
+}
 
 # --- Main ---
 preflight_check