I purchased my thermoworks signals black friday sale of 2020 since I use a fan sometimes, which does take up one of your four ports. I like the app as I can be cooking on a kamado or IVS at home while at work and pull up everything on one screen quickly.
I have had some issues with mine over the years, as I have had 3 signals replaced. The first occurred within a few months of purchase, one of the probe ports came loose and the probe couldn't connect. Thermoworks sent me one out and I had it the next day or day after (along with the jelly beans in every order), and I sent my old one back. Second one I was doing a cook for work and the signals wouldn't connect to the app. I was on the phone with customer support and they advised me to use my tablet or another device to see if it wasn't my phone. When that didn't work, they sent me a new one and I finished the cook by just looking at the screen on the signals since that all still worked.
Overall, I'm still happy with it, and I bought my dad one for Christmas a year or two ago and his has had no issues at all. Now I'm in the market for a meater block or some other type of wireless probe, since the tangling of wires is getting old when cooking a lot of different meats on the same offset, and the wires don't reach all the way across the smoker.