While not widely used in urban areas , LiTZ is used by a number of backcountry, winderness support groups. Its a formally adopted ARRL protocol as noted in the ARRL repeater handbook.
Some repeater controller support this, some ARES/SAR groups monitor for LiTZ.
Since the code is portable to several platforms under the arduino IDE, you should be able to use an esp8266-12 and add wifi capabilities to this. Either show a log of when the litz was trigger or using an outbound wifi connetion SMS page/email when a litz signal is recevied. I dont have time to explore this option as this time but may do so in the near future.. If you give it a try let me know.
In the files section is the arduino software needed for this project. It has a number of optional features that I didnt implement. It has the ability to support a secondary speaker for alerting only with an alarm or you can use as I have chosen to just turn the speaker on. About the only change I might make to the software would be a timeout on how long the speaker is open. If this is used at a monitoring station then triggering and leaving trigged would be fine. For home operations you might not want to come home and fout that sometime during the day the alarm kicked off.
While attended for LITZ wilderness protocol use, it could be modifed to support DTMF paging for an ARES group. Change the code to use whatever tones you want. Single or mutli tone could be supported with minimal code changes.
I put the arduino on a small perf board more as way to mount the unit into the speaker. A little glue from the glue gun on the perf board would allow me to savlage the parts at a later time if I wanted to. I use wirewrap for most of the computer,module connections.
I found that if I used the are around the speaker frame the electroncis would fit and not interfere with the speaker frame. I started with how to get power into the unit. Since this was a ham radio application 12v would be availalbe. Using a 12v to 5v converter and using ham radio standard power poles my power needs were covered. I added a toggle switch from my junk drawer to allow me to turn off and reset the LITZ as needed.
I drilled a hole and mounted the switch and drilled several small holes and with a file fitted the power poles into a hole. Hole ended up a little larger than I would have liked but some super glue and liberal amount of glue from the glue gun it will hold fine.
I was finally able to get this into a non protoype form. I change the code a little to make it more usable. Contruction techniques for the final version was a mix of wire wrapping and some small guage wire soldering. I replaced the relay module I use in my proto type with a much smaller unit to fit in the speaker enclosure.
I found a Kenwood speaker in stock pile and it was large enough to house all the electonics..
When the case is open there is a lot of room around the outside edge. I tried several other speakers but just couldnt find the room and didnt want to use an external box for the electronics.