You need to add mapsApiKey=... to local.properties You have to place scala-compiler.jar and scala-library.jar to tools/ You have to place scala-compiler.jar and scala-library.jar to tools/ ProGuard is required to build! Copy proguard.jar to tools/ -injars ${out.classes.absolute.dir}:${external.libs.dir}:tools/scala-library.jar(!META-INF/MANIFEST.MF,!library.properties) -outjars ${out.absolute.dir}/classes.min.jar -libraryjars ${toString:android.target.classpath} -dontwarn scala.** -dontnote scala.** -dontobfuscate -dontoptimize -printusage ${optimized.dir}/proguard.usage -keep public class * extends android.app.Activity -keep public class * extends android.app.Service -keep public interface scala.ScalaObject -dontskipnonpubliclibraryclasses -dontskipnonpubliclibraryclassmembers -allowaccessmodification Converting compiled files and external libraries into ${intermediate.dex.file}...