diff --git a/Package.swift b/Package.swift
index 78b5a1b..61be855 100644
--- a/Package.swift
+++ b/Package.swift
@@ -5,19 +5,15 @@ import PackageDescription
 
 let package = Package(
     name: "ThreadSafeCollections",
+    platforms: [
+      .iOS(.v12)
+    ],
     products: [
-        // Products define the executables and libraries produced by a package, and make them visible to other packages.
         .library(
             name: "ThreadSafeCollections",
             targets: ["ThreadSafeCollections"]),
     ],
-    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: "ThreadSafeCollections",
             dependencies: []),
diff --git a/Sources/ThreadSafeCollections/ThreadSafeCollections.swift b/Sources/ThreadSafeCollections/ThreadSafeCollections.swift
deleted file mode 100644
index ba94eb1..0000000
--- a/Sources/ThreadSafeCollections/ThreadSafeCollections.swift
+++ /dev/null
@@ -1,3 +0,0 @@
-struct ThreadSafeCollections {
-    var text = "Hello, World!"
-}
diff --git a/Sources/ThreadSafeCollections/ThreadSafeList.swift b/Sources/ThreadSafeCollections/ThreadSafeList.swift
new file mode 100644
index 0000000..7891ae0
--- /dev/null
+++ b/Sources/ThreadSafeCollections/ThreadSafeList.swift
@@ -0,0 +1,91 @@
+import Foundation
+
+public class ThreadSafeList<V> {
+  
+  private var items = [V]()
+  private var itemQueue: DispatchQueue
+  public init(identifier: String = UUID().uuidString) {
+    itemQueue = DispatchQueue(
+      label: "ThreadSafeList.\(String(describing: V.self)).queue.\(identifier)",
+      qos: .userInitiated,
+      attributes: .concurrent,
+      target: DispatchQueue.global(qos: .userInitiated)
+    )
+  }
+  
+  public func get(_ index: Int) -> V? {
+    var value: V?
+    itemQueue.sync { // safely read
+      if self.items.indices.contains(index) {
+        value = self.items[index]
+      } else {
+        value = nil
+      }
+    }
+    return value
+  }
+  
+  public func insert(_ value: V, at index: Int) {
+    itemQueue.async(flags: .barrier) { // safely write
+      self.items.insert(value, at: index)
+    }
+  }
+  
+  @discardableResult public func remove(at index: Int) -> V? {
+    guard let value = get(index) else {
+      // make sure the index exists
+      return nil
+    }
+    itemQueue.async(flags: .barrier) { // safely write
+      self.items.remove(at: index)
+    }
+    return value
+  }
+  
+  public func append(_ value: V) {
+    itemQueue.async(flags: .barrier) { // safely write
+      self.items.append(value)
+    }
+  }
+  
+  public func append(contentsOf values: [V]) {
+    itemQueue.async(flags: .barrier) { // safely write
+      self.items.append(contentsOf: values)
+    }
+  }
+  
+  public func removeAll() {
+    itemQueue.async(flags: .barrier) { // safely write
+      self.items.removeAll()
+    }
+  }
+  
+  public func getAll() -> [V] {
+    var allItems = [V]()
+    itemQueue.sync { // safely read
+      allItems = self.items
+    }
+    return allItems
+  }
+  
+  public func count() -> Int {
+    var count = 0
+    itemQueue.sync { // safely read
+      count = self.items.count
+    }
+    return count
+  }
+  
+  public subscript(index: Int) -> V? {
+    get {
+      return self.get(index)
+    }
+    set(newValue) {
+      if let value = newValue  {
+        self.insert(value, at: index)
+      } else {
+        self.remove(at: index)
+      }
+    }
+  }
+}
diff --git a/Sources/ThreadSafeCollections/ThreadSafeMap.swift b/Sources/ThreadSafeCollections/ThreadSafeMap.swift
new file mode 100644
index 0000000..925983a
--- /dev/null
+++ b/Sources/ThreadSafeCollections/ThreadSafeMap.swift
@@ -0,0 +1,73 @@
+import Foundation
+
+public class ThreadSafeMap<K: Hashable, V> {
+  
+  private var items = [K: V]()
+  private var itemQueue: DispatchQueue
+  
+  public init(identifier: String = UUID().uuidString) {
+    itemQueue = DispatchQueue(
+      label: "ThreadSafeMap.\(String(describing: K.self)).\(String(describing: V.self)).queue.\(identifier)",
+      qos: .userInitiated,
+      attributes: .concurrent,
+      target: DispatchQueue.global(qos: .userInitiated)
+    )
+  }
+  
+  public func get(_ key: K) -> V? {
+    var value: V?
+    itemQueue.sync { // safely read
+      value = self.items[key]
+    }
+    return value
+  }
+  
+  public func put(_ key: K, _ value: V?) {
+    itemQueue.async(flags: .barrier) { // safely write
+      self.items[key] = value
+    }
+  }
+  
+  public func removeAll() {
+    itemQueue.async(flags: .barrier) { // safely write
+      self.items.removeAll()
+    }
+  }
+  
+  public func removeValue(forKey key: K) {
+    itemQueue.async(flags: .barrier) { // safely write
+      self.items.removeValue(forKey: key)
+    }
+  }
+  
+  public func getAll() -> [K: V] {
+    var allItems = [K: V]()
+    itemQueue.sync { // safely read
+      allItems = self.items
+    }
+    return allItems
+  }
+  
+  public func putAll(_ allItems: [K: V]) {
+    itemQueue.async(flags: .barrier) { // safely write
+      self.items = allItems
+    }
+  }
+  
+  public subscript(key: K) -> V? {
+    get {
+      return self.get(key)
+    }
+    set(newValue) {
+      self.put(key, newValue)
+    }
+  }
+  
+  public func count() -> Int {
+    var count = 0
+    itemQueue.sync { // safely read
+      count = self.items.count
+    }
+    return count
+  }
+}
diff --git a/Tests/ThreadSafeCollectionsTests/ThreadSafeCollectionsTests.swift b/Tests/ThreadSafeCollectionsTests/ThreadSafeCollectionsTests.swift
index 1f1e318..84f825e 100644
--- a/Tests/ThreadSafeCollectionsTests/ThreadSafeCollectionsTests.swift
+++ b/Tests/ThreadSafeCollectionsTests/ThreadSafeCollectionsTests.swift
@@ -2,14 +2,42 @@ import XCTest
 @testable import ThreadSafeCollections
 
 final class ThreadSafeCollectionsTests: XCTestCase {
-    func testExample() {
-        // This is an example of a functional test case.
-        // Use XCTAssert and related functions to verify your tests produce the correct
-        // results.
-        XCTAssertEqual(ThreadSafeCollections().text, "Hello, World!")
+  
+  func testMap() {
+    let m = ThreadSafeMap<Int, Int>()
+    (0...99).forEach { i in
+      m.put(i, i)
+      XCTAssertEqual(i, m.get(i))
+      m.removeValue(forKey: i)
+      XCTAssertNil(m.get(i))
+      m[i] = i
+      XCTAssertEqual(i, m[i])
     }
-
-    static var allTests = [
-        ("testExample", testExample),
-    ]
+    XCTAssertEqual(100, m.count())
+    let items = m.getAll()
+    m.removeAll()
+    XCTAssertEqual(0, m.count())
+    m.putAll(items)
+    XCTAssertEqual(100, m.count())
+  }
+  
+  func testList() {
+    let m = ThreadSafeList<Int>()
+    (0...99).forEach { i in
+      m.append(i)
+      XCTAssertEqual(i, m.get(i))
+      let removed = m.remove(at: i)
+      XCTAssertEqual(removed, i)
+      XCTAssertNil(m.get(i))
+      m[i] = i
+      XCTAssertEqual(i, m[i])
+    }
+    XCTAssertEqual(100, m.count())
+    let items = m.getAll()
+    m.removeAll()
+    XCTAssertEqual(0, m.count())
+    m.append(contentsOf: items)
+    XCTAssertEqual(100, m.count())
+  }
+  
 }