IFTTT mostly uses pre-build channels with pre-built actions. However, these are partnerships, i.e. time-consuming to set up and beyond the reach of non-corporate entites. In August 2016, IFTTT brought out the Maker channel. You can now integrate REST-based services.
The problem is, LANnouncer talked to Android devices, either via LAN or SMS. LAN-based devices are probably behind a firewall and SMS doesn’t even have an interface.
This was great for the initial intent of LANnouncer, but not IFTTT compatible.
IFTTT can now talk to the LANNouncer service (completely free – it’s written in Python), and connect to LANNouncer via either GCM, Google Cloud Messaging… which also requires a web server… or the WAN connection.