I have an RTL-SDR v4, and a Raspberry Pi. I am wondering if there is some way to get the ease of use that comes with the flipper zero with the pi. This is ignoring the packaging, and how small the flipper is. And also ignoring the replaying of signals, as additional hardware would be needed.
Universal Radio Hacker probably isn’t as simple as you are hoping, but it should be moderately easy and very powerful https://github.com/jopohl/urh