diff --git a/app/src/test/kotlin/waituntil/AppTest.kt b/app/src/test/kotlin/waituntil/AppTest.kt
deleted file mode 100644
index b39b0d4..0000000
--- a/app/src/test/kotlin/waituntil/AppTest.kt
+++ /dev/null
@@ -1,16 +0,0 @@
-/*
- * This Kotlin source file was generated by the Gradle 'init' task.
- */
-package de.jotoho.waituntil
-
-import kotlin.test.Test
-import kotlin.test.assertNotNull
-
-class AppTest {
-    /*
-    @Test fun appHasAGreeting() {
-        val classUnderTest = App()
-        assertNotNull(classUnderTest.greeting, "app should have a greeting")
-    }
-    */
-}
diff --git a/app/build.gradle.kts b/build.gradle.kts
similarity index 89%
rename from app/build.gradle.kts
rename to build.gradle.kts
index cd8a815..cf34629 100644
--- a/app/build.gradle.kts
+++ b/build.gradle.kts
@@ -6,6 +6,8 @@
  * User Manual available at https://docs.gradle.org/7.2/userguide/building_java_projects.html
  */
 
+import org.jetbrains.kotlin.gradle.tasks.KotlinCompile
+
 plugins {
     // Apply the org.jetbrains.kotlin.jvm Plugin to add support for Kotlin.
     id("org.jetbrains.kotlin.jvm") version "1.+"
@@ -26,7 +28,7 @@ dependencies {
     // Align versions of all Kotlin components
     implementation(platform("org.jetbrains.kotlin:kotlin-bom"))
 
-    // Use the Kotlin JDK 8 standard library.
+    // Use the Kotlin standard library.
     implementation("org.jetbrains.kotlin:kotlin-stdlib")
 
     // Use the Kotlin test library.
@@ -41,7 +43,11 @@ java {
     targetCompatibility = JavaVersion.VERSION_17
 }
 
-tasks.withType<org.jetbrains.kotlin.gradle.tasks.KotlinCompile>() {
+tasks.test {
+    useJUnitPlatform()
+}
+
+tasks.withType<KotlinCompile>() {
         kotlinOptions.jvmTarget = "17"
 }
 
diff --git a/settings.gradle.kts b/settings.gradle.kts
index d59993a..599ab7a 100644
--- a/settings.gradle.kts
+++ b/settings.gradle.kts
@@ -8,4 +8,3 @@
  */
 
 rootProject.name = "waituntil"
-include("app")
diff --git a/app/src/main/kotlin/de/jotoho/waituntil/sleeping.kt b/src/main/kotlin/de/jotoho/waituntil/sleeping.kt
similarity index 94%
rename from app/src/main/kotlin/de/jotoho/waituntil/sleeping.kt
rename to src/main/kotlin/de/jotoho/waituntil/sleeping.kt
index 8feb564..b318873 100644
--- a/app/src/main/kotlin/de/jotoho/waituntil/sleeping.kt
+++ b/src/main/kotlin/de/jotoho/waituntil/sleeping.kt
@@ -1,12 +1,11 @@
 package de.jotoho.waituntil
 
-import java.lang.Math
 import java.time.Instant
 import java.time.ZonedDateTime
 import java.time.format.DateTimeFormatter
 import java.time.format.FormatStyle
 import java.time.temporal.ChronoUnit
-import java.util.TimeZone
+import java.util.*
 
 public fun waitUntilTimeStamp(timestamp: ZonedDateTime) {
     Thread.sleep(Math.max(Instant.now().until(timestamp, ChronoUnit.MILLIS), 0))
diff --git a/app/src/main/kotlin/de/jotoho/waituntil/start.kt b/src/main/kotlin/de/jotoho/waituntil/start.kt
similarity index 85%
rename from app/src/main/kotlin/de/jotoho/waituntil/start.kt
rename to src/main/kotlin/de/jotoho/waituntil/start.kt
index abfdc68..4ed1795 100644
--- a/app/src/main/kotlin/de/jotoho/waituntil/start.kt
+++ b/src/main/kotlin/de/jotoho/waituntil/start.kt
@@ -1,16 +1,6 @@
 package de.jotoho.waituntil
 
-import java.util.Locale
-import java.time.format.DateTimeFormatter
-import java.util.TimeZone
-import java.time.Instant
-import java.time.LocalTime
-import java.time.LocalDate
-import java.time.ZonedDateTime
-import java.time.temporal.ChronoUnit
-
-import de.jotoho.waituntil.waitUntilTimeStamp
-import de.jotoho.waituntil.calculateAndAnnounceTargetTime
+import java.util.*
 
 // This file contains the main function and other utility function necessary for interpreting the terminal arguments.
 // See README.md and LICENSE.md for license information
diff --git a/app/src/main/kotlin/de/jotoho/waituntil/timecalc.kt b/src/main/kotlin/de/jotoho/waituntil/timecalc.kt
similarity index 100%
rename from app/src/main/kotlin/de/jotoho/waituntil/timecalc.kt
rename to src/main/kotlin/de/jotoho/waituntil/timecalc.kt