Preload pages: when checked, preloads the next page for a faster transition. Preload pages is also available in the Page Properties panel, and its settings there have precedence over the project settings.
For example, if you set your project properties to NOT preload pages and later you set page 10 to preload, no pages will preload (as set in this window here), with the exception of page 10, which will preload page 11.
Must be dispabled for using page curl when swiping page
End app. on suspend: quit the application in the case of an interruption (user left the app, phone ring, etc)
Expansion Files panel
Google Play has a 50MB size limit on APK files. Large apps, like storybooks and games, usually are larger than that. Expansion files is a feature offered to allow apps download “the rest of content” above the 50MB (more about here). If your project targets Android devices, this panel will be enabled (in the screenshot above, as the project was created only for iOS devices, the panel is not enabled):
Enable expansion file for Android: if checked, automatically creates code for expansion (files will be downloaded when user opens the app for the first time);
Key: you will need to enter the application key created by Google Play, when you register your application at the store;
Team Project panel
This new panel is useful for projects where team members are working on different projects that, later on, will be merged in just one final project. For example, designer A is working on pages 1 to 15 and designer B, on pages 16 to 30. While designing different projects, when done, all pages will be merged together. In this scenario, designer A will set Start page to 1 and End page to 30. Designer B will set Start page to 16 and end page to auto.
Start page: Set the initial page number of the project;
End page: Set the last page number of the project;
Auto: Set the last page number automatically;
Manual: Set the last page number manually, based on the entry in the text field in the right;