Thanks for the replies and suggestions!
The problem with iDevice apps is they rely solely on data from stations whose readings are often irrelevant to actual location. The only onboard sensors on my 6S+ applicable to weather is a barometer (which without writing code I cannot calibrate). Otherwise, all weather data is pulled from local weather stations.
The weather station nearest my current location is at an airport, 10 miles away, at 682 ft. I'm currently located in a ravine on a ridge at 1853 ft with ~300ft of elevated ridge line behind me and ~50ft of elevation in front of me. It's a semi forested area with 70ft to 90ft tall trees. Operation above tree line is easy if the wind blows from the back side of the ridge. It's something else when coming off the front. At 400 ft its going to be what it's going to be, and probably turbulent at that.
If this were strictly a hobby, I could probably live with iDevice weather & nav apps. Realistically each site I visit will have its own unique flight characteristics and requirements. So I'm always on the lookout for tools that will ensure reasonably safe and dependable flights. Consequently, it can't possibly hurt to use an onsite instrument to pull site specific ground information before launching. Thus the reason for my inquiry.
As for iDevice apps, Avia is an android app not available for iOS (which is my currently preferred platform). I looked at UAVforecast before, and it merits a closer look. I'd prefer a bearing rather than an arrow and am not sure whether the 7 day 'forecast' justifies a $24 "hobby" subscription (only $2 per month) unless it brings something else more immediately useful to the table.
As an aside, I currently run several "weather apps" on my iPhone for general weather conditions including RadarScope Pro (which provides METAR), MyRadar Pro (with AIRMET overlay and wind vectors), Weather Underground, Storm, Dark Skies, and several others. Some of these apps pull data from NOAA and/or Alison House. At the risk of being redundant all these apps provide information based on local, regional, and national NWS data unless the apps specifically link in NWS Cooperative Observer stations.
I also have pilot nav apps with aviation weather (e.g. ForeFlight, etc.). But if I have to go that route I might as well be filing flight plans with local air traffic control (which is outside the topic of this discussion).
Soooo, coming full circle, would still like to know if anyone carries uses any handheld instruments in their kits as part of their preflight or site use?
Cheers!