Firecracker's software is designed to honor all of your historical data, and give you credit for any progress you make in any version of Firecracker. If you are logged in on multiple devices and/or browsers, or you leave multiple versions of Firecracker MD/DO open simultaneously, then I'd suggest hitting the "Hi, YourFirstName" message in the upper-right, and clicking Sync Progress once you're about to get crackin on a new device. This feature "pulls" recent data from the server, which will include any progress you've made on other devices. The "Sync Content" feature similarly "pulls" recent data from our team of authors and editors, including any newly published questions and content. Please don't hesitate to reach out to us directly in the app, or via email to firstname.lastname@example.org if you have any other questions, concerns, comments, or ideas for the Firecracker team!