Control your LibreOffice presentations from your smartphone! Our community has released a new version of the Impress Remote for Android, with various fixes and updates: https://blog.documentfoundation.org/blog/2019/11/14/new-version-of-libreoffice-impress-remote-for-android/
If you want to control Libreoffice Impress presentations, then f-droid already has the "Impress Remote":
You could also install kdeconnect from f-droid and use that to control the presentation using your phone.
Fosstodon is an English speaking Mastodon instance that is open to anyone who is interested in technology; particularly free & open source software.