As Elixir site says "Elixir ships with a great set of tools to ease development". This statement is absolute truth.
Elixir's help system is really phenomenal.
Let's say You are looking for Enum module, but You are not sure about exact name. Just enter E and press TAB - a set of suggestions will auto appear.
Now press dot and TAB - a set of availabe functions within Enum module will appear.
You want to see a signature and usage exaples of some particular function within the moudule? Not a big deal. Just type h Enum.map and You are good to go: