Recommended and mentioned products
Fast application launcher for Linux. Custom shortcuts for web URLs and scripts.
Instant file search, showing results as you type.
For Search I currently use AngrySearch. Which indexes your filesmanually triggered, and then searches that index when you type in the search box.
Omnilauncher for Linux to help you quickly find and run apps and do other useful things.
Coming from Mac OS I missed something similar to spotlight/Alfred. I settled with Albert launcher. It’s pretty customisable and light.