Multi-factor authentication is relevant to achieve higher levels of security, but adoption is hindered by an imbalance between usability and security. The contribution of this project is to develop an application that serves as a secondary authentication factor, with goals of making it simple and secure to use, while at the same time factoring in necessary application security precautions. The requirements are based on an analysis of properties of authentication factors, and the application is developed according to best practices with cybersecurity. The results of testing shows that the requirements are largely met, which concludes the project.