Progressive Web Apps (PWAs) are web apps that use web APIs and features along with progressive enhancement strategy to bring a native app-like user experience to cross-platform web applications. Although Firefox supports many of Progressive Web App APIs, it does not support functionality to install them as a standalone system app with an app-like experience. This functionality is often also known as a Site Specific Browser (SSB). This project creates a custom modified Firefox runtime to allow websites to be installed as standalone apps and provides a console tool and browser extension to install, manage and use them. You can check out the installation and usage instructions on our documentation website. You can also check out the project's source code and more information on the GitHub repository. Note: When updating to 2.17.2, you may see a popup from Firefox that the extension may now collect or transmit the browsing activity. This is because according to the Firefox Add-ons Policies, communication with the native messaging host is considered data collection and transmission. No changes regarding the actual transmission have been made. No personal data leave the computer or are sent to third parties. Browsing data (the current website and manifest URLs) is only sent to the native program when installing a web app and stored locally. Note: I will appreciate it if you read and participate in a GitHub discussion to suggest how to make this project more user-friendly and which features would you like the most. You can also read and participate in a GitHub discussion about the documentation website.