When a block with a pressure plate on top is destroyed, I expected the block above the pressure plate to be updated, but it was not. This bug can be used to create floating sand, floating gravel, floating anvils, floating anything... confirmed on Samsung Galaxy S4 Android 5.0.1 MCPE 0.13 build 5.

gatharian added:
A block update should happen when you break either the pressure plate or the block beneath it. It is expected that the block above should fall in both situations. Here's an example: If I were to place a block beneath with a torch on it, then break the block that the torch is on, the block above will fall instead of staying in mid air.

Original report:
When placing an anvil or sand on top of a pressure plate, then breaking the block that the pressure plate is on, the anvil will not fall.