In ITU R.2 (the Americas) it seems to be almost all 144.39 MHz. There is some HF stuff, too, mostly on the 30-m band but I don't know specific frequencies. In other ITU regions, there are other "default" frequencies on, at least, the 2-m band.

Closest I come is "DPRS" which is APRS-ish via D-STAR.

Do *I* do actual #APRS? No. Do I want to do it? Yes. Do I use my lack of antennas as an excuse for this and other things? I'm sorry, that's all the time we have today.