Melt Modifier
The melt modifier allows you to distort mesh objects in a way that simulates a melting effect. You can control the object melt behavior by setting the solidity parameter at the middle of the melt rollout. Presets exist for ice and glass etc, you can also set your own value by choosing custom.
Axis to melt controls which axis the effect is to be applied to.
Melt amount controls how much of the object is to be distorted, with 100 being completely "melted". Spread is how much the mesh deforms and spreads out at the base in relation to the current melt amount.
Melt is great for fluid effects where you can set it to melt over time by keyframing the melt amount and other variables. Another use would be for simulating a fluid impacting a surface, like water droplets falling onto tiles.