diff --git a/.DS_Store b/.DS_Store
index 0cb9b08..6c877d4 100644
Binary files a/.DS_Store and b/.DS_Store differ
diff --git a/.swiftpm/xcode/package.xcworkspace/contents.xcworkspacedata b/.swiftpm/xcode/package.xcworkspace/contents.xcworkspacedata
new file mode 100644
index 0000000..919434a
--- /dev/null
+++ b/.swiftpm/xcode/package.xcworkspace/contents.xcworkspacedata
@@ -0,0 +1,7 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<Workspace
+   version = "1.0">
+   <FileRef
+      location = "self:">
+   </FileRef>
+</Workspace>
diff --git a/Package.swift b/Package.swift
new file mode 100644
index 0000000..3300d1d
--- /dev/null
+++ b/Package.swift
@@ -0,0 +1,22 @@
+// swift-tools-version:5.1
+// The swift-tools-version declares the minimum version of Swift required to build this package.
+
+import PackageDescription
+
+let package = Package(
+    name: "BKCountDownTimer",
+    dependencies: [
+        // Dependencies declare other packages that this package depends on.
+        // .package(url: /* package url */, from: "1.0.0"),
+    ],
+    targets: [
+        // Targets are the basic building blocks of a package. A target can define a module or a test suite.
+        // Targets can depend on other targets in this package, and on products in packages which this package depends on.
+        .target(
+            name: "BKCountDownTimer",
+            dependencies: []),
+        .testTarget(
+            name: "BKCountDownTimerTests",
+            dependencies: ["BKCountDownTimer"]),
+    ]
+)
diff --git a/Sources/CircleBase.swift b/Sources/BKCountDownTimer/CircleBase.swift
similarity index 100%
rename from Sources/CircleBase.swift
rename to Sources/BKCountDownTimer/CircleBase.swift
diff --git a/Sources/CircleCount.swift b/Sources/BKCountDownTimer/CircleCount.swift
similarity index 100%
rename from Sources/CircleCount.swift
rename to Sources/BKCountDownTimer/CircleCount.swift
diff --git a/Sources/CircleTic.swift b/Sources/BKCountDownTimer/CircleTic.swift
similarity index 100%
rename from Sources/CircleTic.swift
rename to Sources/BKCountDownTimer/CircleTic.swift
diff --git a/Sources/CircleTimer.swift b/Sources/BKCountDownTimer/CircleTimer.swift
similarity index 100%
rename from Sources/CircleTimer.swift
rename to Sources/BKCountDownTimer/CircleTimer.swift
diff --git a/Tests/BKCountDownTimerTests/BKCountDownTimerTests.swift b/Tests/BKCountDownTimerTests/BKCountDownTimerTests.swift
new file mode 100644
index 0000000..2145d75
--- /dev/null
+++ b/Tests/BKCountDownTimerTests/BKCountDownTimerTests.swift
@@ -0,0 +1,47 @@
+import XCTest
+import class Foundation.Bundle
+
+final class BKCountDownTimerTests: XCTestCase {
+    func testExample() throws {
+        // This is an example of a functional test case.
+        // Use XCTAssert and related functions to verify your tests produce the correct
+        // results.
+
+        // Some of the APIs that we use below are available in macOS 10.13 and above.
+        guard #available(macOS 10.13, *) else {
+            return
+        }
+
+        let fooBinary = productsDirectory.appendingPathComponent("BKCountDownTimer")
+
+        let process = Process()
+        process.executableURL = fooBinary
+
+        let pipe = Pipe()
+        process.standardOutput = pipe
+
+        try process.run()
+        process.waitUntilExit()
+
+        let data = pipe.fileHandleForReading.readDataToEndOfFile()
+        let output = String(data: data, encoding: .utf8)
+
+        XCTAssertEqual(output, "Hello, world!\n")
+    }
+
+    /// Returns path to the built products directory.
+    var productsDirectory: URL {
+      #if os(macOS)
+        for bundle in Bundle.allBundles where bundle.bundlePath.hasSuffix(".xctest") {
+            return bundle.bundleURL.deletingLastPathComponent()
+        }
+        fatalError("couldn't find the products directory")
+      #else
+        return Bundle.main.bundleURL
+      #endif
+    }
+
+    static var allTests = [
+        ("testExample", testExample),
+    ]
+}
diff --git a/Tests/BKCountDownTimerTests/XCTestManifests.swift b/Tests/BKCountDownTimerTests/XCTestManifests.swift
new file mode 100644
index 0000000..ea60859
--- /dev/null
+++ b/Tests/BKCountDownTimerTests/XCTestManifests.swift
@@ -0,0 +1,9 @@
+import XCTest
+
+#if !canImport(ObjectiveC)
+public func allTests() -> [XCTestCaseEntry] {
+    return [
+        testCase(BKCountDownTimerTests.allTests),
+    ]
+}
+#endif
diff --git a/Tests/LinuxMain.swift b/Tests/LinuxMain.swift
new file mode 100644
index 0000000..162f210
--- /dev/null
+++ b/Tests/LinuxMain.swift
@@ -0,0 +1,7 @@
+import XCTest
+
+import BKCountDownTimerTests
+
+var tests = [XCTestCaseEntry]()
+tests += BKCountDownTimerTests.allTests()
+XCTMain(tests)