I read that limited broadcast address will be dropped by the router. So, it's not used in the layer-3 (Network layer), where IP addresses are meant to be used. So, where exactly is it used?
Any broadcasts are limited to a layer-2 domain, which is bounded by a layer-3 device (router).
An application designer, needing to send broadcasts on any subnet where the application may be run, could use the Limited Broadcast address as a hard-coded address rather than spending the time to figure out the subnet broadcast address for the subnet on which the application finds itself.