Legitimate loading screen?

I was wondering if there are any services or such for a legit loading screen, where it actually depends on items in the workspace and assets and so on.

I seen loading screens, and same with the wiki, it just has a loop function or a tick() function and slowly moves the bar at a fixed rate.

I understand how to script so im not requesting a script, just any services or a idea on how to load it depending on the legit loading status.

** Not A Request **