To answer your question about the Tapping Legends button effect. You can always use a GUI gradient and paste this code into a local script. Just make sure you make a variable for the gradient. You can also make it slower or faster by changing the wait values or the +1 to anything.
while true do
repeat
Gradient.Rotation = Gradient.Rotation +1
wait(0.05)
until Gradient.Rotation >= 360
wait(0.05)
Gradient.Rotation = 0
end