Vendor BLE sniffer firmware (nRF52 DK / dongle) with a Wireshark plugin. Easy and well-documented, but follows a single connection and is less capable than Sniffle for adversarial work.
Still offered by Nordic and distributed as the nrfutil ble-sniffer command; the latest package in Nordic's registry is 0.21.0 from August 2026. Source · checked 2026-09-28