diff --git a/devtools/GameSaveAnalysis.py b/devtools/GameSaveAnalysis.py
new file mode 100644
index 0000000..ea1c19b
--- /dev/null
+++ b/devtools/GameSaveAnalysis.py
@@ -0,0 +1,106 @@
+import matplotlib.pyplot as plt
+
+def read_data(file_path):
+    """
+    Read data from a file and return the x and y values.
+
+    Args:
+        file_path (str): The path to the data file.
+
+    Returns:
+        tuple: A tuple containing the x and y values. If the file is not found or has invalid data, returns empty lists.
+    """
+    with open(file_path, 'r') as file:
+        lines = file.readlines()
+        if len(lines) >= 3:
+            data_line = lines[2].strip()
+            if data_line.endswith('-1'):
+                data_values = [float(val) for val in data_line[:-2].split()]  # Remove the '-1' terminator
+                x = list(range(1, len(data_values) + 1))
+                return x, data_values
+    return [], []
+
+def get_user_input():
+    """
+    Prompt the user to enter file numbers and validate the input.
+
+    Returns:
+        list: A list of selected file numbers.
+    """
+    print("Enter the file numbers you want to display (0-19), separated by spaces:")
+    user_input = input().strip()
+    try:
+        file_numbers = [int(num) for num in user_input.split() if 0 <= int(num) <= 19]
+        return file_numbers
+    except ValueError:
+        print("Invalid input. Please enter numbers between 0 and 19.")
+        return get_user_input()
+
+def get_graph_type():
+    """
+    Prompt the user to choose between percentage change or absolute value graph.
+
+    Returns:
+        str: The chosen graph type ('pct' for percentage change, 'abs' for absolute value).
+    """
+    print("Do you want to show percentage change or absolute value graph?")
+    print("Enter 'pct' for percentage change or 'abs' for absolute value:")
+    graph_type = input().strip().lower()
+    if graph_type == 'pct':
+        return 'pct'
+    elif graph_type == 'abs':
+        return 'abs'
+    else:
+        print("Invalid input. Please enter 'pct' or 'abs'.")
+        return get_graph_type()
+
+# Get user input for file selection
+selected_files = get_user_input()
+
+# Get user input for graph type
+graph_type = get_graph_type()
+
+data = []
+
+for file_num in selected_files:
+    file_path = f"saves/save/{file_num}.save"
+    try:
+        x, y = read_data(file_path)
+        if x and y:  # Only add if we have data
+            if graph_type == 'pct':
+                percentage_changes = []
+                for i in range(1, len(y)):
+                    if y[i-1] != 0:  # Avoid division by zero
+                        pct_change = ((y[i] - y[i-1]) / y[i-1]) * 100
+                    else:
+                        pct_change = 0  # or float('inf') if you prefer
+                    percentage_changes.append(pct_change)
+                data.append((x[:-1], percentage_changes, file_num))  # Exclude the last index for pct_change
+            else:
+                data.append((x, y, file_num))
+    except FileNotFoundError:
+        print(f"File not found: {file_path}")
+    except Exception as e:
+        print(f"Error reading {file_path}: {e}")
+
+if not data:
+    print("No valid data to plot.")
+else:
+    fig, ax = plt.subplots(figsize=(10, 6))
+
+    for x, y, file_num in data:
+        ax.plot(x, y, label=f"File {file_num}")
+
+    if graph_type == 'pct':
+        graph_title = "Percentage Change of Values from Selected Data Files"
+        y_label = "Percentage Change (%)"
+    else:
+        graph_title = "Absolute Values from Selected Data Files"
+        y_label = "Value"
+
+    ax.set_title(graph_title)
+    ax.set_xlabel("Index")
+    ax.set_ylabel(y_label)
+    ax.legend()
+    plt.grid(True)
+    plt.show()
diff --git a/devtools/coveralls.sh b/devtools/coveralls.sh
new file mode 100644
index 0000000..4254fd1
--- /dev/null
+++ b/devtools/coveralls.sh
@@ -0,0 +1,16 @@
+virtualenv _venv --clear
+source _venv/scripts/activate
+pip install cpp-coveralls
+
+branches="`git branch -lr | cut -c 10- | cut -d ' ' -f 1 | grep -v HEAD`"
+
+for branch in $branches
+do
+    echo $branch
+    git checkout $branch
+    make clean
+    CXXFLAGS=--coverage make goto
+    gcov src/*.cpp -o .
+    coveralls
+    rm *.gcda *.gcno *.gcov
+done
diff --git a/devtools/peupdate.exe b/devtools/peupdate.exe
new file mode 100644
index 0000000..582fe94
Binary files /dev/null and b/devtools/peupdate.exe differ
diff --git a/devtools/peupdate.txt b/devtools/peupdate.txt
new file mode 100644
index 0000000..01819bd
--- /dev/null
+++ b/devtools/peupdate.txt
@@ -0,0 +1 @@
+_backup\peupdate.exe stocksim-msvc.exe -r -f -t 0 -l -c
\ No newline at end of file
diff --git a/devtools/stocksim-icon.ico b/devtools/stocksim-icon.ico
new file mode 100644
index 0000000..c571f4f
Binary files /dev/null and b/devtools/stocksim-icon.ico differ