Previous miniWOL versions proved that just reading the specifications of Wake on LAN and testing with your own equipment is not going to result in a 100% perfect application, as it seems that certain machines prefer to see a broadcast over the network instead of a specific IP address.
In this new version, you can still retrieve the Mac Address based on IP address, and use a broadcast mask (255.255.255.255 is the default). This should help with certain setups like Synology devices.
This update applies to Windows and MacOS versions of miniWOL.
Note: I have just uploaded a revised v1.2 (Friday Dec. 9 2016) which fixes sending a WOL when miniWOL starts for those servers that have been tagged as such.