If you have Windows as your OS, it is likely that you have used the Microsoft Calculator app. The app has the same functions as a standard calculator, as well as functions for scientific and programming calculators. Additionally, the app allows you to convert various units and currencies.
What drew me to the project was that while simple, the calculator is still highly functional. For someone with limited experience in both programing projects and open source, working with this repository would provide me with the right amount of challenge. It would also be straightforward since it is still within the scope of my knowledge. Furthermore, the Calculator is written in c++, which is a language I have enough experience in that it would not pose as an additional challenge.
Finally, improving an app I have experience using and I can grasp the full function of makes me feel more comfortable with the idea of working with open source projects. While I found other projects that were very interesting, such as face recognition and self-driving car programs, working on them felt too daunting as a start.