Hi JenniferCK, could I ask you to clarify something: your question was posted under Android, but you mentioned a desktop icon. What kind of system is having this problem? A moderator can move your question based on your answer.

Sorry, it's an Android phone, not great with the lingo! Home screen? But it's not even in the downloaded apps... Trying to get this one fixed before I switch phones! Which is hopefully tomorrow

Actually I lost other things as well... maybe it's the phone?!

Hmm, it's weird to lose a few things selectively.

I think in order to confirm whether Firefox is installed, you might need to check either in the Google Play app, current applications, or in Settings, under application management.

You might also check your other home screen panels in case Firefox somehow got bumped to a different panel.