diff --git a/audio-echo/app/src/main/cpp/CMakeLists.txt b/audio-echo/app/src/main/cpp/CMakeLists.txt
index 23a06ce08..deffbc97b 100644
--- a/audio-echo/app/src/main/cpp/CMakeLists.txt
+++ b/audio-echo/app/src/main/cpp/CMakeLists.txt
@@ -1,9 +1,9 @@
 cmake_minimum_required(VERSION 3.22.1)
 project(echo LANGUAGES C CXX)
 
-add_compile_options(-Wall -Wextra -Werror)
+include(AppLibrary)
 
-add_library(echo
+add_app_library(echo
     SHARED
     audio_main.cpp
     audio_player.cpp
diff --git a/base/src/main/cpp/CMakeLists.txt b/base/src/main/cpp/CMakeLists.txt
index c70b4410d..9e4fb549f 100644
--- a/base/src/main/cpp/CMakeLists.txt
+++ b/base/src/main/cpp/CMakeLists.txt
@@ -1,9 +1,9 @@
 cmake_minimum_required(VERSION 3.22.1)
 project(Base LANGUAGES CXX)
 
-add_compile_options(-Wall -Werror -Wextra)
+include(AppLibrary)
 
-add_library(base
+add_app_library(base
     STATIC
     logging.cpp
 )
diff --git a/bitmap-plasma/app/src/main/cpp/CMakeLists.txt b/bitmap-plasma/app/src/main/cpp/CMakeLists.txt
index f068dc03a..37eef2aba 100644
--- a/bitmap-plasma/app/src/main/cpp/CMakeLists.txt
+++ b/bitmap-plasma/app/src/main/cpp/CMakeLists.txt
@@ -1,9 +1,9 @@
 cmake_minimum_required(VERSION 3.22.1)
-project(BitmapPlasma LANGUAGES C)
+project(BitmapPlasma LANGUAGES CXX)
 
-set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wall -Werror -Wno-unused-function")
+include(AppLibrary)
 
-add_library(plasma SHARED plasma.c)
+add_app_library(plasma SHARED plasma.cpp)
 
 # Include libraries needed for plasma lib
 target_link_libraries(plasma
diff --git a/bitmap-plasma/app/src/main/cpp/plasma.c b/bitmap-plasma/app/src/main/cpp/plasma.cpp
similarity index 97%
rename from bitmap-plasma/app/src/main/cpp/plasma.c
rename to bitmap-plasma/app/src/main/cpp/plasma.cpp
index b9e03efee..cb9e3f1eb 100644
--- a/bitmap-plasma/app/src/main/cpp/plasma.c
+++ b/bitmap-plasma/app/src/main/cpp/plasma.cpp
@@ -108,16 +108,10 @@ static __inline__ Fixed angle_sin(Angle a) {
   return angle_sin_tab[(uint32_t)a & (ANGLE_2PI - 1)];
 }
 
-static __inline__ Fixed angle_cos(Angle a) { return angle_sin(a + ANGLE_PI2); }
-
 static __inline__ Fixed fixed_sin(Fixed f) {
   return angle_sin(ANGLE_FROM_FIXED(f));
 }
 
-static __inline__ Fixed fixed_cos(Fixed f) {
-  return angle_cos(ANGLE_FROM_FIXED(f));
-}
-
 /* Color palette used for rendering the plasma */
 #define PALETTE_BITS 8
 #define PALETTE_SIZE (1 << PALETTE_BITS)
@@ -180,8 +174,7 @@ static void fill_plasma(AndroidBitmapInfo* info, void* pixels, double t) {
 #define YT1_INCR FIXED_FROM_FLOAT(1 / 100.)
 #define YT2_INCR FIXED_FROM_FLOAT(1 / 163.)
 
-  int yy;
-  for (yy = 0; yy < info->height; yy++) {
+  for (uint32_t yy = 0; yy < info->height; yy++) {
     uint16_t* line = (uint16_t*)pixels;
     Fixed base = fixed_sin(yt1) + fixed_sin(yt2);
     Fixed xt1 = xt10;
@@ -335,7 +328,7 @@ static void stats_endFrame(Stats* s) {
 }
 
 JNIEXPORT void JNICALL Java_com_example_plasma_PlasmaView_renderPlasma(
-    JNIEnv* env, jobject obj, jobject bitmap, jlong time_ms) {
+    JNIEnv* env, jclass, jobject bitmap, jlong time_ms) {
   AndroidBitmapInfo info;
   void* pixels;
   int ret;
diff --git a/build-logic/src/main/java/com/android/ndk/samples/buildlogic/AndroidApplicationConventionPlugin.kt b/build-logic/src/main/java/com/android/ndk/samples/buildlogic/AndroidApplicationConventionPlugin.kt
index 6bd96f0c4..80085c899 100644
--- a/build-logic/src/main/java/com/android/ndk/samples/buildlogic/AndroidApplicationConventionPlugin.kt
+++ b/build-logic/src/main/java/com/android/ndk/samples/buildlogic/AndroidApplicationConventionPlugin.kt
@@ -30,6 +30,7 @@ class AndroidApplicationConventionPlugin : Plugin<Project> {
                     externalNativeBuild {
                         cmake {
                             arguments.add("-DANDROID_SUPPORT_FLEXIBLE_PAGE_SIZES=ON")
+                            arguments.add("-DCMAKE_MODULE_PATH=${rootDir.resolve("cmake")}")
                         }
                     }
 
diff --git a/build-logic/src/main/java/com/android/ndk/samples/buildlogic/AndroidLibraryConventionPlugin.kt b/build-logic/src/main/java/com/android/ndk/samples/buildlogic/AndroidLibraryConventionPlugin.kt
index 1ac2746d4..c697c99e6 100644
--- a/build-logic/src/main/java/com/android/ndk/samples/buildlogic/AndroidLibraryConventionPlugin.kt
+++ b/build-logic/src/main/java/com/android/ndk/samples/buildlogic/AndroidLibraryConventionPlugin.kt
@@ -33,6 +33,7 @@ class AndroidLibraryConventionPlugin : Plugin<Project> {
                     externalNativeBuild {
                         cmake {
                             arguments.add("-DANDROID_SUPPORT_FLEXIBLE_PAGE_SIZES=ON")
+                            arguments.add("-DCMAKE_MODULE_PATH=${rootDir.resolve("cmake")}")
                         }
                     }
                     ndk {
diff --git a/cmake/AppLibrary.cmake b/cmake/AppLibrary.cmake
new file mode 100644
index 000000000..e44102fe4
--- /dev/null
+++ b/cmake/AppLibrary.cmake
@@ -0,0 +1,15 @@
+include_guard()
+
+# Wrapper for add_library which enables common options we want for all
+# libraries.
+function(add_app_library name)
+    cmake_parse_arguments(PARSE_ARGV 1 arg "" "" "")
+    add_library(${name} ${arg_UNPARSED_ARGUMENTS})
+
+    target_compile_options(${name}
+        PRIVATE
+        -Wall
+        -Wextra
+        -Werror
+    )
+endfunction()
diff --git a/vectorization/src/main/cpp/CMakeLists.txt b/vectorization/src/main/cpp/CMakeLists.txt
index a51799c64..a26b18370 100644
--- a/vectorization/src/main/cpp/CMakeLists.txt
+++ b/vectorization/src/main/cpp/CMakeLists.txt
@@ -1,11 +1,10 @@
 cmake_minimum_required(VERSION 3.22.1)
 project(Vectorization LANGUAGES CXX)
 
-add_compile_options(-Wall -Wextra -Werror)
-
+include(AppLibrary)
 find_package(base REQUIRED CONFIG)
 
-add_library(app
+add_app_library(app
     SHARED
     benchmark.cpp
     jni.cpp