Downloading the software is only half the equation. To use the sniffer, you need supported hardware. The nRF Sniffer is compatible with almost all Nordic Development Kits (DKs) and the nRF52840 Dongle (PCA10059).
If a central device (like a smartphone) fails to connect to a peripheral, the sniffer can reveal if the connection request was ever sent, if the peripheral ignored it, or if the parameters (connection interval, latency) were rejected. nrf sniffer for bluetooth le download nordic