I do something similar, a basic screenshot or two of the gauges and use the mark-up app in Preview to type in a few notes such as where I could wade, fish caught and present, strength of current, etc. Not a regular fishing log, just something to give me an idea of where I can get away with hipboots instead of wet wading or waisthighs. IOW, mostly about the streambed and how the numbers relate on any given year, updated after large floods or shifts in structure.I'm in the process of stetting standards for CFS and Gauge Height using the USGS Current water flow for the rivers and streams I fish in Michigan, including water temperature.
I never saw the utility in anything more specific than that for my fishing and anything more might actually be a detrimental influence at times. I’m often trying something new which makes many days a new horizon in some large or small way. Add to that improvements in technique and I wouldn’t be able make heads or tails out of a log entry from two years ago. Logging would be unintentionally restricting and perhaps a bit stifling.
Too many variables in the waters and species I fish and given my own explorative behavioral quirks, anything appearing as clarity would often be more forced interpretation (perhaps illusion) than reality. This has been and still remains a long and winding journey as opposed to laps for me. May always be that way, I don’t know.