For example here I have this object with custom methods like the “start_timer()” method and even though it is there I don’t see it in the available methods.
Is there an addon that can show these methods and or even variables of custom objects in suggestion popup menu?
This is already a thing if you use Type hinting in GDScript. If you assign something to a variable, add a class_name at the top of said script, then from another script, do something like: var myClass: className = whatever
Then in the script where you want to access something, do:
This should give you hints on what functions you have in your TestClass.