Meta Search - Search your Desktop, Google Drive, Dropbox, Gmail, Evernote.
Google Cloud Search - Search across all your company's content in G Suite.
FYI - Find your documents, like magic 🔮
xendo - Fast search for all your work. See all your important documents, emails, contacts and updates with one search.
CerebroApp - Productivity booster with a brain
Cloudo - Search & access all your cloud apps from one place