diff --git a/tools/zentry/main.cpp b/tools/zentry/main.cpp
new file mode 100644
index 0000000..fd3e533
--- /dev/null
+++ b/tools/zentry/main.cpp
@@ -0,0 +1,11 @@
+#include "mainwindow.h"
+
+#include <QApplication>
+
+int main(int argc, char *argv[])
+{
+    QApplication a(argc, argv);
+    MainWindow w;
+    w.show();
+    return a.exec();
+}
diff --git a/tools/zentry/mainwindow.cpp b/tools/zentry/mainwindow.cpp
new file mode 100644
index 0000000..f56395d
--- /dev/null
+++ b/tools/zentry/mainwindow.cpp
@@ -0,0 +1,120 @@
+#include "mainwindow.h"
+#include "ui_mainwindow.h"
+
+#include "compression.h"
+#include "qfiledialog.h"
+
+#include <QMessageBox>
+#include <QLabel>
+#include <QFile>
+#include <QVBoxLayout>
+
+MainWindow::MainWindow(QWidget *parent)
+    : QMainWindow{parent} {
+    setWindowTitle("Zentry Tool");
+    setMinimumSize(250, 150);
+    setMaximumSize(250, 150);
+    setWindowFlags(Qt::Dialog | Qt::MSWindowsFixedSizeDialogHint);
+
+    QLabel *dragLabel = new QLabel(this);
+    dragLabel->setText("Drop file here...");
+    dragLabel->setAlignment(Qt::AlignHCenter | Qt::AlignVCenter);
+    dragLabel->setStyleSheet("QLabel {"
+                             "  color: white;"
+                             "  background-color: grey;"
+                             "}"
+                             "QLabel::hover "
+                             "{"
+                             "  background-color: black;"
+                             "}");
+
+    setCentralWidget(dragLabel);
+}
+
+MainWindow::~MainWindow() {
+
+}
+
+void MainWindow::dragEnterEvent(QDragEnterEvent *event) {
+    const QMimeData *mimeData = event->mimeData();
+    bool goodDrag = true;
+    if (mimeData->hasUrls()) {
+        qDebug() << mimeData->urls();
+    } else {
+        goodDrag = false;
+    }
+    if (goodDrag) {
+        event->acceptProposedAction();
+    }
+}
+
+void MainWindow::dragMoveEvent(QDragMoveEvent *event) {
+    Q_UNUSED(event);
+}
+
+void MainWindow::dragLeaveEvent(QDragLeaveEvent *event) {
+    Q_UNUSED(event);
+}
+
+void MainWindow::dropEvent(QDropEvent *event) {
+    const QMimeData *mimeData = event->mimeData();
+    if (mimeData->hasUrls()) {
+        foreach (const QUrl &url, mimeData->urls()) {
+            const QString fileName = url.toString().split('/').last();
+            QMessageBox msgBox;
+            msgBox.setWindowTitle("Handle File");
+            msgBox.setText("Choose how to handle " + fileName);
+
+            QPushButton *compressButton = msgBox.addButton(tr("Compress"), QMessageBox::AcceptRole);
+            QPushButton *decompressButton = msgBox.addButton(tr("Decompress"), QMessageBox::RejectRole);
+            QPushButton *cancelButton = msgBox.addButton(tr("Cancel"), QMessageBox::RejectRole);
+            msgBox.exec();
+
+            if ((QPushButton*)msgBox.clickedButton() == compressButton) {
+                // Compress
+            } else if ((QPushButton*)msgBox.clickedButton() == decompressButton) {
+                // Decompress
+                QFile compressedFile(url.toLocalFile());
+                if (!compressedFile.open(QIODevice::ReadOnly)) {
+                    qDebug() << QString("Failed to open %1!").arg(fileName);
+                    continue;
+                }
+
+                const QByteArray compressedData = compressedFile.readAll();
+                QByteArray decompressedData;
+                if (compressedData.left(2).toHex() == "7801") {
+                    qDebug() << "Detected zlib data! (No Compression/low)";
+                    decompressedData = Compression::DecompressZLIB(compressedData);
+                } else if (compressedData.left(2).toHex() == "785e") {
+                    qDebug() << "Detected zlib data! (Fast Compression)";
+                    decompressedData = Compression::DecompressZLIB(compressedData);
+                } else if (compressedData.left(2).toHex() == "789c") {
+                    qDebug() << "Detected zlib data! (Default Compression)";
+                    decompressedData = Compression::DecompressZLIB(compressedData);
+                } else if (compressedData.left(2).toHex() == "78da") {
+                    qDebug() << "Detected zlib data! (Best Compression)";
+                    decompressedData = Compression::DecompressZLIB(compressedData);
+                } else {
+                    qDebug() << "Invalid zlib header!";
+                    continue;
+                }
+
+                if (decompressedData.isEmpty()) {
+                    qDebug() << "Zlib output was empty!";
+                    continue;
+                }
+
+                const QString decompressedPath = QFileDialog::getSaveFileName(this, "Choose save name");
+                QFile decompressedFile(decompressedPath);
+                if (!decompressedFile.open(QIODevice::WriteOnly)) {
+                    qDebug() << QString("Failed to open %1!").arg(decompressedPath.split('/').last());
+                    continue;
+                }
+                decompressedFile.write(decompressedData);
+                decompressedFile.close();
+            } else if ((QPushButton*)msgBox.clickedButton() == cancelButton) {
+                // Cancel
+            }
+        }
+    }
+}
diff --git a/tools/zentry/mainwindow.h b/tools/zentry/mainwindow.h
new file mode 100644
index 0000000..4995cf5
--- /dev/null
+++ b/tools/zentry/mainwindow.h
@@ -0,0 +1,32 @@
+#ifndef MAINWINDOW_H
+#define MAINWINDOW_H
+
+#include <QMainWindow>
+#include <QDebug>
+#include <QMimeData>
+#include <QDragEnterEvent>
+
+QT_BEGIN_NAMESPACE
+namespace Ui {
+class MainWindow;
+}
+QT_END_NAMESPACE
+
+class MainWindow : public QMainWindow
+{
+    Q_OBJECT
+
+public:
+    MainWindow(QWidget *parent = nullptr);
+    ~MainWindow();
+
+protected:
+    void dragEnterEvent(QDragEnterEvent *event) override;
+    void dragMoveEvent(QDragMoveEvent *event) override;
+    void dragLeaveEvent(QDragLeaveEvent *event) override;
+    void dropEvent(QDropEvent *event) override;
+
+private:
+    Ui::MainWindow *ui;
+};
+#endif // MAINWINDOW_H
diff --git a/tools/zentry/mainwindow.ui b/tools/zentry/mainwindow.ui
new file mode 100644
index 0000000..6a8c885
--- /dev/null
+++ b/tools/zentry/mainwindow.ui
@@ -0,0 +1,22 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<ui version="4.0">
+ <class>MainWindow</class>
+ <widget class="QMainWindow" name="MainWindow">
+  <property name="geometry">
+   <rect>
+    <x>0</x>
+    <y>0</y>
+    <width>1006</width>
+    <height>600</height>
+   </rect>
+  </property>
+  <property name="windowTitle">
+   <string>MainWindow</string>
+  </property>
+  <widget class="QWidget" name="centralwidget">
+   <layout class="QGridLayout" name="gridLayout"/>
+  </widget>
+ </widget>
+ <resources/>
+ <connections/>
+</ui>
diff --git a/tools/zentry/zentry.pro b/tools/zentry/zentry.pro
index 68b8e1e..aaee86d 100644
--- a/tools/zentry/zentry.pro
+++ b/tools/zentry/zentry.pro
@@ -2,26 +2,29 @@ QT += core widgets gui multimedia
 
 RC_ICONS = zentry.ico
 
-SUBDIRS += zentry
-
 CONFIG += c++17
 
 SOURCES += \
-    zentrymain.cpp \
-    zentrywindow.cpp
+    main.cpp \
+    mainwindow.cpp
 
 HEADERS += \
-    zentrywindow.h
+    mainwindow.h
+
+FORMS += \
+    mainwindow.ui
 
 LIBS += \
+    -L$$OUT_PWD/../../libs/ -lcore \
     -L$$OUT_PWD/../../libs/ -lcompression \
     -L$$PWD/../../third_party/xbox_sdk/lib -lxcompress64
 
 INCLUDEPATH += \
+    $$PWD/../../libs/core \
     $$PWD/../../libs/compression \
     $$PWD/../../third_party/xbox_sdk/include
 
 DEPENDPATH += \
+    $$PWD/../../libs/core \
     $$PWD/../../libs/compression \
     $$PWD/../../third_party/xbox_sdk/include
-