diff --git a/NativeAppTemplateTests/Data/ViewModels/TabViewModelTest.swift b/NativeAppTemplateTests/Data/ViewModels/TabViewModelTest.swift
new file mode 100644
index 0000000..8b611a7
--- /dev/null
+++ b/NativeAppTemplateTests/Data/ViewModels/TabViewModelTest.swift
@@ -0,0 +1,35 @@
+//
+//  TabViewModelTest.swift
+//  NativeAppTemplate
+//
+
+import Foundation
+@testable import NativeAppTemplate
+import Testing
+
+@MainActor
+@Suite
+struct TabViewModelTest {
+    @Test
+    func initialState() {
+        let viewModel = TabViewModel()
+
+        #expect(viewModel.selectedTab == .shops)
+        for tab in MainTab.allCases {
+            #expect(viewModel.showingDetailView[tab] == false)
+        }
+    }
+
+    @Test
+    func showingDetailView() {
+        let viewModel = TabViewModel()
+
+        viewModel.showingDetailView[.shops] = true
+        #expect(viewModel.showingDetailView[.shops] == true)
+        #expect(viewModel.showingDetailView[.scan] == false)
+        #expect(viewModel.showingDetailView[.settings] == false)
+
+        viewModel.showingDetailView[.shops] = false
+        #expect(viewModel.showingDetailView[.shops] == false)
+    }
+}
diff --git a/NativeAppTemplateTests/Extensions/StringExtensionsTest.swift b/NativeAppTemplateTests/Extensions/StringExtensionsTest.swift
new file mode 100644
index 0000000..adfcf1b
--- /dev/null
+++ b/NativeAppTemplateTests/Extensions/StringExtensionsTest.swift
@@ -0,0 +1,38 @@
+//
+//  StringExtensionsTest.swift
+//  NativeAppTemplate
+//
+
+import CoreGraphics
+@testable import NativeAppTemplate
+import Testing
+
+struct StringExtensionsTest {
+    @Test(arguments: [
+        ("hello123", true),
+        ("ABC", true),
+        ("abc", true),
+        ("123", true),
+        ("Hello World", false),
+        ("hello!", false),
+        ("hello@world", false),
+        ("", false)
+    ])
+    func isAlphanumeric(input: String, expected: Bool) {
+        #expect(input.isAlphanumeric() == expected)
+    }
+
+    @Test
+    func isAlphanumericIgnoringDiacritics() {
+        #expect("hello123".isAlphanumeric(ignoreDiacritics: true) == true)
+        #expect("ABC123".isAlphanumeric(ignoreDiacritics: true) == true)
+        #expect("hello world".isAlphanumeric(ignoreDiacritics: true) == false)
+        #expect("".isAlphanumeric(ignoreDiacritics: true) == false)
+    }
+
+    @Test
+    func imageGeneration() {
+        let image = "A".image(size: CGSize(width: 50, height: 50))
+        #expect(image != nil)
+    }
+}
diff --git a/NativeAppTemplateTests/Models/ItemTagStateTest.swift b/NativeAppTemplateTests/Models/ItemTagStateTest.swift
new file mode 100644
index 0000000..9ecc864
--- /dev/null
+++ b/NativeAppTemplateTests/Models/ItemTagStateTest.swift
@@ -0,0 +1,21 @@
+//
+//  ItemTagStateTest.swift
+//  NativeAppTemplate
+//
+
+@testable import NativeAppTemplate
+import Testing
+
+struct ItemTagStateTest {
+    @Test
+    func initFromValidStrings() {
+        #expect(ItemTagState(string: "idled") == .idled)
+        #expect(ItemTagState(string: "completed") == .completed)
+    }
+
+    @Test
+    func initFromUnknownStringDefaultsToIdled() {
+        #expect(ItemTagState(string: "unknown") == .idled)
+        #expect(ItemTagState(string: "") == .idled)
+    }
+}
diff --git a/NativeAppTemplateTests/Models/ItemTagTypeTest.swift b/NativeAppTemplateTests/Models/ItemTagTypeTest.swift
new file mode 100644
index 0000000..a367d44
--- /dev/null
+++ b/NativeAppTemplateTests/Models/ItemTagTypeTest.swift
@@ -0,0 +1,27 @@
+//
+//  ItemTagTypeTest.swift
+//  NativeAppTemplate
+//
+
+@testable import NativeAppTemplate
+import Testing
+
+struct ItemTagTypeTest {
+    @Test
+    func initFromValidStrings() {
+        #expect(ItemTagType(string: "server") == .server)
+        #expect(ItemTagType(string: "customer") == .customer)
+    }
+
+    @Test
+    func initFromUnknownStringDefaultsToServer() {
+        #expect(ItemTagType(string: "unknown") == .server)
+        #expect(ItemTagType(string: "") == .server)
+    }
+
+    @Test
+    func toJsonRoundtrip() {
+        #expect(ItemTagType(string: ItemTagType.server.toJson()) == .server)
+        #expect(ItemTagType(string: ItemTagType.customer.toJson()) == .customer)
+    }
+}
diff --git a/NativeAppTemplateTests/Models/ScanStateTest.swift b/NativeAppTemplateTests/Models/ScanStateTest.swift
new file mode 100644
index 0000000..bac41f8
--- /dev/null
+++ b/NativeAppTemplateTests/Models/ScanStateTest.swift
@@ -0,0 +1,27 @@
+//
+//  ScanStateTest.swift
+//  NativeAppTemplate
+//
+
+@testable import NativeAppTemplate
+import Testing
+
+struct ScanStateTest {
+    @Test
+    func initFromValidStrings() {
+        #expect(ScanState(string: "unscanned") == .unscanned)
+        #expect(ScanState(string: "scanned") == .scanned)
+    }
+
+    @Test
+    func initFromUnknownStringDefaultsToUnscanned() {
+        #expect(ScanState(string: "unknown") == .unscanned)
+        #expect(ScanState(string: "") == .unscanned)
+    }
+
+    @Test
+    func toJsonRoundtrip() {
+        #expect(ScanState(string: ScanState.unscanned.toJson()) == .unscanned)
+        #expect(ScanState(string: ScanState.scanned.toJson()) == .scanned)
+    }
+}
diff --git a/NativeAppTemplateTests/Utilities/MessageBusTest.swift b/NativeAppTemplateTests/Utilities/MessageBusTest.swift
new file mode 100644
index 0000000..649c2d5
--- /dev/null
+++ b/NativeAppTemplateTests/Utilities/MessageBusTest.swift
@@ -0,0 +1,81 @@
+//
+//  MessageBusTest.swift
+//  NativeAppTemplate
+//
+
+@testable import NativeAppTemplate
+import Testing
+
+@MainActor
+@Suite
+struct MessageBusTest {
+    @Test
+    func initialState() {
+        let bus = MessageBus()
+
+        #expect(bus.currentMessage == nil)
+        #expect(bus.messageVisible == false)
+    }
+
+    @Test
+    func postMessageSetsCurrentMessage() {
+        let bus = MessageBus()
+
+        bus.post(message: Message(level: .success, message: "Done"))
+
+        #expect(bus.currentMessage != nil)
+        #expect(bus.currentMessage?.message == "Done")
+        #expect(bus.currentMessage?.level == .success)
+        #expect(bus.messageVisible == true)
+    }
+
+    @Test
+    func postErrorMessage() {
+        let bus = MessageBus()
+
+        bus.post(message: Message(level: .error, message: "Failed", autoDismiss: false))
+
+        #expect(bus.currentMessage?.level == .error)
+        #expect(bus.currentMessage?.message == "Failed")
+        #expect(bus.currentMessage?.autoDismiss == false)
+        #expect(bus.messageVisible == true)
+    }
+
+    @Test
+    func dismiss() {
+        let bus = MessageBus()
+
+        bus.post(message: Message(level: .success, message: "Done"))
+        #expect(bus.messageVisible == true)
+
+        bus.dismiss()
+        #expect(bus.messageVisible == false)
+    }
+
+    @Test
+    func postReplacesExistingMessage() {
+        let bus = MessageBus()
+
+        bus.post(message: Message(level: .success, message: "First"))
+        bus.post(message: Message(level: .error, message: "Second"))
+
+        #expect(bus.currentMessage?.message == "Second")
+        #expect(bus.currentMessage?.level == .error)
+    }
+
+    @Test
+    func snackbarState() {
+        let message = Message(level: .error, message: "Error occurred")
+        let snackbarState = message.snackbarState
+
+        #expect(snackbarState.status == .error)
+        #expect(snackbarState.message == "Error occurred")
+    }
+
+    @Test
+    func messageLevelSnackbarStatus() {
+        #expect(Message.Level.error.snackbarStatus == .error)
+        #expect(Message.Level.warning.snackbarStatus == .warning)
+        #expect(Message.Level.success.snackbarStatus == .success)
+    }
+}
diff --git a/NativeAppTemplateTests/Utilities/UtilityTest.swift b/NativeAppTemplateTests/Utilities/UtilityTest.swift
new file mode 100644
index 0000000..61e123f
--- /dev/null
+++ b/NativeAppTemplateTests/Utilities/UtilityTest.swift
@@ -0,0 +1,53 @@
+//
+//  UtilityTest.swift
+//  NativeAppTemplate
+//
+
+import Foundation
+@testable import NativeAppTemplate
+import Testing
+
+struct UtilityTest {
+    @Test
+    func scanUrlContainsExpectedParams() {
+        let url = Utility.scanUrl(itemTagId: "abc-123", itemTagType: "server")
+
+        #expect(url.absoluteString.contains("item_tag_id=abc-123"))
+        #expect(url.absoluteString.contains("type=server"))
+    }
+
+    @Test
+    func scanUrlCustomerType() {
+        let url = Utility.scanUrl(itemTagId: "xyz-456", itemTagType: "customer")
+
+        #expect(url.absoluteString.contains("item_tag_id=xyz-456"))
+        #expect(url.absoluteString.contains("type=customer"))
+    }
+
+    @Test(arguments: [
+        ("", true),
+        ("   ", true),
+        ("\n", true),
+        (" \t\n ", true),
+        ("hello", false),
+        (" hello ", false)
+    ])
+    func isBlank(text: String, expected: Bool) {
+        #expect(Utility.isBlank(text) == expected)
+    }
+
+    @Test(arguments: [
+        ("test@example.com", true),
+        ("user.name+tag@domain.co", true),
+        ("user@domain.com", true),
+        ("", false),
+        ("notanemail", false),
+        ("@domain.com", false),
+        ("user@", false),
+        ("user@.com", false)
+    ])
+    func validateEmail(email: String, expected: Bool) {
+        #expect(Utility.validateEmail(email) == expected)
+    }
+
+}