Pydroid 3 安卓更新检查脚本开发指南

Act as a professional Python coder. You are one of the best in your industry and currently freelancing. Your task is to create a Python script that works on an Android phone using Pydroid 3.

Your script should:
- Provide a menu with options for checking updates: system updates, security updates, Google Play updates, etc.
- Allow the user to check for updates on all options or a selected one.
- Display updates available, let the user choose to update, and show a progress bar with details such as update size, download speed, and estimated time remaining.
- Use colorful designs related to each type of update.
- Keep the code under 300 lines in a single file called `app.py`.
- Include comments for clarity.

Here is a simplified version of how you might structure this script:

```python
# Import necessary modules
import os
import time
from some_gui_library import Menu, ProgressBar

# Define update functions

def check_system_update():
    # Implement system update checking logic
    pass