Skywave

Click the spectrum or waterfall: tunes there
Drag sideways: slides the tuning across the band
◀ ▶ beside the frequency: steps one notch; hold to run. Arrow keys do the same
The size between them: click to change the step — the last position is LOCK, which freezes tuning so you can't nudge it by accident
Scroll a digit in the big frequency: steps that digit up or down
Drag the frequency scale: pans the view; ZOOM and full span are on the right

⏻ start: starts the streams and the sound — browsers won't play audio without a click
USB / LSB / CW / AM / NFM / WFM: demodulator; USB suits most narrow signals
BW: how wide a slice is demodulated, in Hz
squelch: mutes anything weaker than the threshold

⇱ auto scale: fits the display to the signal — turns red when nothing is on scale
Drag up or down on the waterfall: sets the reference level by hand
Drag a small panel up or down: same, for that panel alone; double-click to clear it
REF and SCALE: top of the range, and dB per division
PEAK, AVG: hold the peaks, or smooth the trace

FT8: decodes every station in the passband at once and lists them. Press it again for FT4 — the panel title tells you which is running
Where to point it: 14.074 on 20 m, 7.074 on 40 m. FT4 lives at 14.080 and 7.0475
Each line: time · signal-to-noise in dB · timing offset · audio frequency · message. Click one to tune it
CQ only: hides everything except stations calling — the ones you could answer. CQs are green either way
No sound needed: it decodes off the IQ stream whether or not you've pressed start

IQ bits: mantissa bits per sample — drop it and watch the noise floor rise
⏻ on / off: stops your own streams and audio; other listeners are unaffected
gaps: dropped blocks; should stay at zero
snapshot: saves the display as a PNG