Interesting. I’ve Never heard of those. Care to elaborate on them a bit?
Caltopo was originally Web-only (desktop) for a few years but got a big following especially amongst emergency responders like wildfire crews because it had special layers just for that. But like other apps it also had the usual private-property and so on. What I liked about it was it was really easy to plan routes and see their elevation profiles. I've saved myself quite a few nasty gully-climbs just knowing if I shifted my route 200yds I could avoid it, which is not always obvious on topos in the field. In the past year or two they came out with a mobile app and I've started using it as well.
Locus Pro excels at data tracking - not just the route you took, but POI's and other details. It'll show things other apps don't like very detailed stats on your hike, down to time spent moving vs resting, avg pace, etc. I'm a data geek so when I first started using tools like this, it was appealing to me. It also transitions well between different nav modes, making it easy to spot something a few miles across a valley, hike out to my truck, then plan a drive out to another FS road to try to get access to the other side of it.
Neither app is specifically designed for hunting, but then again, if you think about the features you use in OnX, most aren't really HUNT specific either. Yes, they have hunt-specific icons for POIs you might mark but other apps do, too. It has public/private layers, but so do other apps (including the two above). You can share data points - but they only make it easy if the other person also has OnX (with Locus and Caltopo I can just text the coordinates and my buddy can use whatever app they want to open it.)
I'm not at all saying OnX is bad - far from it. But if you want something cheaper than the $35-$50/yr (and increasing) they're asking, Caltopo has a free edition and mobile+offline is $20/yr. Locus Pro was $4.99 the last I checked but you had to pay an extra $0.50 or so per state you wanted offline. YMMV but I find the two together to be more functional and feature-rich, although OnX usually has the most up to date satellite layers if you care about that.