[yencabulator]

Try https://www.peakfinder.com/ -- I use the Android app all the time (I have no memory of paying for it, though, maybe it used to be free?)

[bradrn]

I’ve been using such tools already (in particular https://www.udeuschle.de/panoramas/makepanoramas_en.htm). But for smaller or more distant features, I’ve found it can be difficult to correlate their physical appearance with their appearance on the diagram. A calibration tool like hdersch’s would make this much easier!