diff --git a/.gitignore b/.gitignore
index 016a01a..1ec15d1 100644
--- a/.gitignore
+++ b/.gitignore
@@ -6,3 +6,4 @@
 *.sync-conflict-*
 node_modules/
 .env
+*.xcodeproj
diff --git a/Apps/MagnumOpus/ContentView.swift b/Apps/MagnumOpus/ContentView.swift
new file mode 100644
index 0000000..3385d8c
--- /dev/null
+++ b/Apps/MagnumOpus/ContentView.swift
@@ -0,0 +1,13 @@
+import SwiftUI
+
+struct ContentView: View {
+	var body: some View {
+		NavigationSplitView {
+			Text("Sidebar")
+		} content: {
+			Text("Thread List")
+		} detail: {
+			Text("Detail")
+		}
+	}
+}
diff --git a/Apps/MagnumOpus/MagnumOpusApp.swift b/Apps/MagnumOpus/MagnumOpusApp.swift
new file mode 100644
index 0000000..7c37a07
--- /dev/null
+++ b/Apps/MagnumOpus/MagnumOpusApp.swift
@@ -0,0 +1,13 @@
+import SwiftUI
+
+@main
+struct MagnumOpusApp: App {
+	var body: some Scene {
+		WindowGroup {
+			ContentView()
+		}
+		#if os(macOS)
+		.defaultSize(width: 1200, height: 800)
+		#endif
+	}
+}
diff --git a/Apps/MagnumOpusTests/AppTests.swift b/Apps/MagnumOpusTests/AppTests.swift
new file mode 100644
index 0000000..d43245d
--- /dev/null
+++ b/Apps/MagnumOpusTests/AppTests.swift
@@ -0,0 +1,9 @@
+import Testing
+
+@Suite("App")
+struct AppTests {
+	@Test("placeholder")
+	func placeholder() {
+		#expect(true)
+	}
+}
diff --git a/Apps/project.yml b/Apps/project.yml
new file mode 100644
index 0000000..0ad7544
--- /dev/null
+++ b/Apps/project.yml
@@ -0,0 +1,72 @@
+name: MagnumOpus
+options:
+  bundleIdPrefix: de.felixfoertsch
+  deploymentTarget:
+    macOS: "15.0"
+    iOS: "18.0"
+  xcodeVersion: "16.0"
+  indentWidth: 4
+  tabWidth: 4
+  usesTabs: true
+packages:
+  MagnumOpusCore:
+    path: ../Packages/MagnumOpusCore
+targets:
+  MagnumOpus-macOS:
+    type: application
+    platform: macOS
+    sources:
+      - path: MagnumOpus
+    settings:
+      base:
+        PRODUCT_NAME: MagnumOpus
+        PRODUCT_BUNDLE_IDENTIFIER: de.felixfoertsch.MagnumOpus
+        DEVELOPMENT_TEAM: NG5W75WE8U
+        SWIFT_STRICT_CONCURRENCY: complete
+        SWIFT_VERSION: "6.0"
+        MACOSX_DEPLOYMENT_TARGET: "15.0"
+        GENERATE_INFOPLIST_FILE: YES
+    dependencies:
+      - package: MagnumOpusCore
+        product: Models
+      - package: MagnumOpusCore
+        product: MailStore
+      - package: MagnumOpusCore
+        product: IMAPClient
+      - package: MagnumOpusCore
+        product: SyncEngine
+  MagnumOpus-iOS:
+    type: application
+    platform: iOS
+    sources:
+      - path: MagnumOpus
+    settings:
+      base:
+        PRODUCT_NAME: MagnumOpus
+        PRODUCT_BUNDLE_IDENTIFIER: de.felixfoertsch.MagnumOpus
+        DEVELOPMENT_TEAM: NG5W75WE8U
+        SWIFT_STRICT_CONCURRENCY: complete
+        SWIFT_VERSION: "6.0"
+        IPHONEOS_DEPLOYMENT_TARGET: "18.0"
+        TARGETED_DEVICE_FAMILY: "1,2"
+        GENERATE_INFOPLIST_FILE: YES
+    dependencies:
+      - package: MagnumOpusCore
+        product: Models
+      - package: MagnumOpusCore
+        product: MailStore
+      - package: MagnumOpusCore
+        product: IMAPClient
+      - package: MagnumOpusCore
+        product: SyncEngine
+  MagnumOpusTests:
+    type: bundle.unit-test
+    platform: macOS
+    sources:
+      - path: MagnumOpusTests
+    dependencies:
+      - target: MagnumOpus-macOS
+    settings:
+      base:
+        SWIFT_VERSION: "6.0"
+        GENERATE_INFOPLIST_FILE: YES