LibreOffice Viewer for Android
Our community is working on a LibreOffice Viewer app for Android devices. It is currently in beta status and not available for end users, but more information is available on this wiki page. If you have some technical knowledge and want to help us test and improve it, you can download the plain apk and sideload it on your device.
Impress Remote for Android and iOS
The Impress Remote is a handy tool for controlling Impress slideshow presentations from a mobile device. For more information and to download the application, visit the Impress Remote page.