reduced minSdkVersion to 15

README.md

@@ -11,6 +11,8 @@ The app will exit on the first touch event.
 Dependencies
 ------------
 
+The minimum required version of Android is 4.0.3 (Ice Cream Sandwich MR1).
+
 This project depends on the Allegro game development library (http://liballeg.org);
 the dependency is automatically resolved by Android Studio using the Maven AAR
 distribution of Allegro (https://bintray.com/liballeg/maven).

app/build.gradle

@@ -4,7 +4,7 @@ android {
     compileSdkVersion 27
     defaultConfig {
         applicationId "com.tksls.yellowrectangle"
-        minSdkVersion 23
+        minSdkVersion 15
         targetSdkVersion 27
         versionCode 1
         versionName "1.0"