Is there a mod for minecraft the has atimer for a tree to tell how long it has to grow?

The problem with trees is that they don't really count down. Every few in-game seconds the system checks to see if a sapling can grow, if it can the game randomly determines whether it does or not.

There's no percentage grown for trees, it either grows or it doesn't. The tree might grow on the first check, it might take 100 checks.

The WAILA (What Am I Looking At) mod is the closest I have ever seen, it shows you how close most crops are to growing.