diff --git a/app.py b/app.py
new file mode 100644
index 0000000..bc7c1db
--- /dev/null
+++ b/app.py
@@ -0,0 +1,71 @@
+from tkinter import *
+from tkinter import filedialog
+from pathlib import Path
+from util import Util
+from functools import partial
+from image import ImageWindow
+
+
+class App:
+    def __init__(self, root):
+        super().__init__()
+        self.selected_folder = ""
+        self.found_images = []
+        self.timer = 0
+        self.title = Label(root, text="Drawing Training")
+        self.title.pack()
+
+        self.folder_selector = Button(root, text="Select a folder", command=self.select_folder)
+        self.folder_selector.pack()
+
+        self.folder_name = Label(root, text="Folder : " + self.selected_folder)
+        self.folder_name.pack()
+
+        self.images_len = Label(root, text="Found : " + str(len(self.found_images)))
+        self.images_len.pack()
+
+        self.button_frame = Frame(root)
+        self.button_frame.pack(fill=X)
+
+        timers = [30, 45, 60, 120, 300, 600]
+        self.buttons = []
+        i = 0
+        for i in timers:
+            t = i
+            new_button = Button(self.button_frame, text=Util.format_seconds(t),
+                                command=partial(self.set_timer_in_seconds, t))
+            # new_button.pack(side="left")
+            self.buttons.append(new_button)
+            self.button_frame.columnconfigure(i, weight=1)
+            new_button.grid(row=0, column=i, sticky=W + E)
+            i += 1
+
+        self.launch_button = Button(root, text="Let's draw!", command=self.lets_draw, state="disabled")
+        self.launch_button.pack(side="bottom")
+        self.image_window = ImageWindow(root)
+
+    def lets_draw(self):
+        self.image_window.lets_draw(self.found_images, self.timer)
+
+    def select_folder(self):
+        self.selected_folder = filedialog.askdirectory()
+        self.found_images = list(
+            p.resolve() for p in Path(self.selected_folder).glob("**/*") if p.suffix in {".jpg", ".gif", ".png"})
+        self.folder_name.config(text="Folder : " + self.selected_folder)
+        self.images_len.config(text="Found : " + str(len(self.found_images)))
+        self.check_lets_draw()
+
+    def check_lets_draw(self):
+        if self.selected_folder != "" and len(self.found_images) > 0 and self.timer != 0:
+            self.launch_button.config(state="normal")
+        else:
+            self.launch_button.config(state="disabled")
+
+    def set_timer_in_seconds(self, user_data):
+        self.timer = user_data
+        for button in self.buttons:
+            if button['text'] == Util.format_seconds(self.timer):
+                button.config(bg="blue")
+            else:
+                button.config(bg="gray85")
+        self.check_lets_draw()
diff --git a/image.py b/image.py
new file mode 100644
index 0000000..ac23f61
--- /dev/null
+++ b/image.py
@@ -0,0 +1,85 @@
+import random
+from tkinter import *
+from PIL import ImageTk, Image
+
+
+class ImageWindow:
+    def __init__(self, window):
+        self.window = Toplevel(window)
+        self.window.title("Image")
+        self.window.geometry("1280x1024")
+        self.images = []
+        self.timer = 0
+        self.timer_label = None
+        self.timer_check = None
+
+    @staticmethod
+    def maintain_aspect_ratio(event, aspect_ratio):
+        new_width = event.width
+        new_height = event.height
+
+        new_aspect_ratio = new_width / new_height
+
+        # Decide which dimension controls.
+        if new_aspect_ratio > aspect_ratio:
+            # Use width as the controlling dimension.
+            desired_width = new_width
+            desired_height = int(new_width / aspect_ratio)
+        else:
+            # Use height as the controlling dimension.
+            desired_height = new_height
+            desired_width = int(new_height * aspect_ratio)
+
+        event.widget.resize(f'{desired_width}x{desired_height}')
+        # Override if necessary.
+        # if new_width != desired_width or new_height != desired_height:
+        #     # Manually give it the proper dimensions.
+        #     return "break"  # Block further processing of this event.
+
+    def update_timer(self, current):
+        current -= 1
+        if current > 0:
+            self.timer_label.configure(text=current)
+            self.timer_check = self.window.after(1000, self.update_timer, current)
+        else:
+            self.window.after_cancel(self.timer_check)
+
+    def lets_draw(self, images, timer):
+        self.images = images
+        self.timer = timer
+
+        canvas = Canvas(self.window)
+        canvas.pack(fill=BOTH, expand=1)
+
+        self.timer_label = Label(self.window, text="")
+        self.timer_label.pack(side=BOTTOM)
+
+        random.shuffle(self.images)
+
+        image_timer = timer
+
+        self.display_new_image()
+        timer_check = self.window.after(1000, self.update_timer, image_timer)
+
+    def display_new_image(self):
+        ma = self.window.winfo_toplevel()
+        w, h = ma.winfo_width(), ma.winfo_height()
+
+        image_path = self.images[0]
+        self.images.pop(0)
+        image = Image.open(image_path)
+
+        if image.size[0] > w or image.size[1] > h:
+            if w < 3 or h < 3:  # too small
+                return  # do nothing
+            image.thumbnail((w - 2, h - 2), Image.ANTIALIAS)
+            print("resized: win %s >= img %s", (w, h), image.size)
+
+        image_to_display = ImageTk.PhotoImage(image)
+
+        image_label = Label(self.window, image=image_to_display)
+        # image_label.bind('<Configure>', lambda event: self.maintain_aspect_ratio(event, 1280 / 1024))
+        image_label.image = image_to_display
+        image_label.pack(side="top", fill="both", expand=1)
+        # Position image
+        # image_label.place(x=0, y=0)
diff --git a/main.py b/main.py
index a96f760..65c674c 100644
--- a/main.py
+++ b/main.py
@@ -1,61 +1,16 @@
-import dearpygui.dearpygui as dpg
-from pathlib import Path
-
-dpg.create_context()
-
-selected_folder = ""
-found_images = []
-timer = 0
-
-with dpg.theme() as blue_theme:
-    with dpg.theme_component(dpg.mvAll):
-        dpg.add_theme_color(dpg.mvThemeCol_FrameBg, (0, 0, 200), category=dpg.mvThemeCat_Core)
+from tkinter import *
+from app import App
 
 
-def setTimerInSeconds(sender, app_data, user_data):
-    timer=user_data
-    print(sender)
-    print(dpg.get_item_theme(sender))
-    dpg.bind_item_theme(sender, blue_theme)
-    print(dpg.get_item_theme(sender))
+def main():
+    root = Tk()
+    root.title("Drawing Training!")
+    root.geometry("300x600")
+
+    app = App(root)
+
+    root.mainloop()
 
 
-def callback(sender, app_data):
-    selected_folder = app_data['file_path_name']
-    found_images = list(p.resolve() for p in Path(selected_folder).glob("**/*") if p.suffix in {".jpg", ".gif", ".png"})
-    dpg.set_value("folder_text", "Folder : " + selected_folder)
-    dpg.set_value("found_images_text", "Found : " + str(len(found_images)))
-    print('OK was clicked.')
-    print("Sender: ", sender)
-    print("App Data: ", app_data)
-
-
-def cancel_callback(sender, app_data):
-    print('Cancel was clicked.')
-    print("Sender: ", sender)
-    print("App Data: ", app_data)
-
-
-with dpg.file_dialog(directory_selector=True, show=False, callback=callback, tag="file_dialog_id",
-                     cancel_callback=cancel_callback, width=700, height=400):
-    dpg.add_file_extension("Images (*.jpg *.gif *.png){.jpg,.gif,.png}", color=(0, 255, 255, 255))
-
-with dpg.window(label="Drawing Training", width=300, height=800, pos=(0, 0), no_title_bar=True):
-    dpg.add_text("Drawing Training")
-    dpg.add_button(label="Select a folder", callback=lambda: dpg.show_item("file_dialog_id"))
-    dpg.add_text("Folder : " + selected_folder, tag="folder_text")
-    dpg.add_text("Found : " + str(len(found_images)), tag="found_images_text")
-    with dpg.group(horizontal=True):
-        dpg.add_button(label="30s", callback=setTimerInSeconds, user_data=30, tag="timer_30")
-        dpg.add_button(label="45s", callback=setTimerInSeconds, user_data=45, tag="timer_45")
-        dpg.add_button(label="1m", callback=setTimerInSeconds, user_data=1*60, tag="timer_60")
-        dpg.add_button(label="2m", callback=setTimerInSeconds, user_data=2*60, tag="timer_120")
-        dpg.add_button(label="5m", callback=setTimerInSeconds, user_data=5*60, tag="timer_300")
-        dpg.add_button(label="10m", callback=setTimerInSeconds, user_data=10*60, tag="timer_600")
-    dpg.add_button(label="Let's draw!")
-
-dpg.create_viewport(title='Drawing Training', width=300, height=600)
-dpg.setup_dearpygui()
-dpg.show_viewport()
-dpg.start_dearpygui()
-dpg.destroy_context()
+if __name__ == '__main__':
+    main()
diff --git a/util.py b/util.py
new file mode 100644
index 0000000..327d844
--- /dev/null
+++ b/util.py
@@ -0,0 +1,24 @@
+class Util:
+    @staticmethod
+    def format_seconds(seconds):
+        hours = None
+        minutes = seconds / 60
+        if minutes >= 1:
+            if minutes >= 60:
+                hours = int(minutes / 60)
+                minutes = int(minutes % 60)
+            else:
+                minutes = int(minutes)
+            seconds = seconds % 60
+        else:
+            minutes = None
+
+        time = ""
+        if hours is not None and hours != 0:
+            time += str(hours) + "h"
+        if minutes is not None and minutes != 0:
+            time += str(minutes) + "m"
+        if seconds is not None and seconds != 0:
+            time += str(seconds) + "s"
+
+        return time