There's certainly a lot of positive feedback out there for GAIA GPS on the hiking sites, and apparently there were some significant upgrades in mid-2020:
https://www.adventurealan.com/huge-improvements-next-gen-gaia-gps-hiking-app/

Does anyone have any experience with the AllTrails Pro app?
(https://www.alltrails.com/pro )

The one-year plan at $30 seems steep, but the $60 for 3 years seems not too bad. I've used their website a bit, and it seems competent.

Hmmm: here's a mammoth GAIA GPS vs. All-Trails review by a long-term AllTrails user about what things were important to him (offline maps being a must-have) and why he switched to GAIA GPS last here:
https://www.n1clc.com/2020/09/revisting-alltrails-vs-gaia-from-hams.html?showComment=1600265444687

Here are some other comparative reviews that include both:

(Nov 2020): https://takeahike.us/alltrails-vs-gaia-gps/

GAIA GPS, Alltrails and other apps. They like Greentracks for offline maps (Android only)

https://besthiking.net/best-hiking-apps-test-review/

https://www.territorysupply.com/alltrails-vs-gaia-gps

(note this next review is on the Gaia GPS site ...)
https://blog.gaiagps.com/gaia-gps-vs-alltrails-2/

(The above was posted in the other thread, but I wanted to reply on this one).

Thanks! I've installed the app and downloading it now. I work with a lot of Boy Scouts for whom an annual subscription might be prohibitive - I'll see if this would work for them.

Gaia GPS has been my go-to for several years; others have already covered Gaia pretty well in this thread.

While I still love and use Gaia, I recently started using CalTopo.com more. It isn't as polished as Gaia but has some features that make it more useful in some circumstances:

• Printing Ability - CalTopo allows you to print maps in any scale and datum directly on your computer as well as send them to Mountyn.co Mountyn.co for professionally printed maps. With Gaia, the printed maps are similar to Google Map printouts, and you cannot print them to a specific scale without a lot of trial and error. For many, this will be a non-issue; however, if you want to print paper maps to use with a GPS, GAIA fails here.
• Geospatial PDFs - GAIA doesn't allow the import or creation of Geospatial (georeferenced PDFs). Again, for most users, this isn't a required feature. For others, this gives CalTopo the ability to use maps from many sources that produce GeoPDFs, AND CalTopo can create GeoPDFs for sharing.
• Less built-in map sources, but more data. GAIA dominates the market on map and imagery sources. CalTopo has fewer sources but has some unique data available to the paid user; fire activity (including real-time fire and smoke detection), weather, wind plotting, and sun exposure, to name a few.

For many, Gaia will still win, but CalTopo is worth looking at if you want some more "professional" features.

"real-time fire and smoke detection" - I did that once, a long time ago, sitting in a 100' steel tower atop the Rincon Mts. in AZ. Learned a lot about survival that summer.....

I bet!

It is pretty cool (and really useful) to be able to pull out a laptop or tablet and see how a fire is developing before getting deployed.

With today's mega burns, you need all the technology you can muster. Our house was threatened by a fire three years ago, and the size and rapid rate of spread was truly awesome - quite beyond anything in my experience.