This new tool is for some mod creator or mod user to find out block ID and mob health,but not just that,this indicator can detect BLOCK DAMAGE!That mean you can see the block real name but not just its original name(for example:a stain clay contain a lot of color,it will tell you the exact name of the block)
MINECRAFT PE
Damage And Block Indicator
When pointing to a door.It says undefined
Ah...that is a serious problem, and I found out sideways log dont work too