Glasen: A simple watch-clock as an app

A watch-clock (German Glasenuhr) is a historical, mechanical time signal used on ships to structure the crew's watch periods. A ship's bell strikes every half hour, with the number of strikes increasing over a four-hour watch and then starting over again.

This Android app brings this maritime time signal to your smartphone. It simulates the traditional bell strikes and allows you to customize the sounds. However, the app is not just a simple clock; it also serves as a practical learning project. It was developed to demonstrate modern programming techniques and best practices in Android development.

The key technical aspects that were implemented and tested in this app include:

  • User Interface Design: The development of a clean and intuitive design with current technologies.
  • Artificial Intelligence: The use of AI tools to optimize the development process, for example, in code generation or error analysis.
  • Precise Alarms: The implementation of reliable alarm functions that ensure the bell strikes are played at the exact correct time, even when the screen is off or the app is running in the background.

The privacy policy is available here. The test version of Glasen is available as a on Google Play.

BoatBook: A booking calendar for club boats

Logo BoatBookBoatBook is a booking calendar for the club's boats. I developed it to simplify the organization of the club's own boats for members.

Here’s an overview of the main functions:

  • Check availability: The calendar shows when boats are in use. This allows members to see who is on the water with which boat at any time.
  • Book boats: Members can reserve a boat using the calendar.
  • Notifications: The relevant boat managers are automatically notified of every booking request. Users also receive a notification as soon as their booking has been confirmed or rejected.
  • Store documents: The app offers the option to store important documents such as manuals, forms, or links in a central location.

The goal of BoatBook is to facilitate the booking of club boats and make the processes more transparent.

WarnAttachment: Protection from malicious attachments in Thunderbird

WarnAttachment Logo

The Thunderbird add-on Warn­Attachment is an extension I developed to improve the security of handling email attachments. Since its release on May 1, 2017, it has protected users from the risks associated with potentially dangerous file attachments. Over 1,000 users now use the add-on daily. It's now available in eight languages, including German, English, French, Spanish, and many more, which makes me very happy.

The core function of WarnAttachment is to provide an extra layer of security. For file types considered unsafe, such as scripts or documents with macros, the add-on triggers a warning before the file is opened. This warning gives you the option to confirm or cancel the action, allowing you to make a conscious decision. Particularly risky formats, such as executable files (.exe), are completely blocked by default to protect you from accidentally running malware.

The add-on is customizable, so every user can configure the security levels to suit their needs. You can adjust the settings so that file types are either only warned about or blocked directly.

In an era where malicious email attachments are one of the most common attack strategies, WarnAttachment is a valuable tool for making your email communication more secure.