I've been out of the know for quite a while, so I'm not sure what's out there. Are there any apps that have GPS maps of off-road trails, ORV parks, etc, mainly Katemcy or Hot Springs.

 

Sometimes I use OnX Offroad maps. It costs to have, but if you add a trail now and then it's free. The problem it OnX (and others) is that trail status changes often. Many of the trails that show up on apps may be closed for one reason or another before you have a chance to ride them. Also, I found several user-submitted trails that clearly go to areas that have been off-limits for years - even though the trails were recently submitted. Pretty much soured me on OnX. I don't think any app is really up-to-date.

I have been doing my own trail research. I use OnX, All Trails, and other sources and combine them with official resources. For example, online National Forest Motor Vehicle Use Maps (MVUM) are usually up-to-date. I'll overlay the maps onto Google Earth and zoom in to see the trails with satellite views. If they line up with the app version, great! If not, at least I know where the no-go areas are before I get there.

I often go a step further and map a track on Google Earth that I can extract to a KML file. It's easy to convert KML to other formats. I use GPX since I have a lot of Garmin devices. I also use the free version of Locus Maps on my cell phone, which gives me a good view of the selected trails even offline. Just need to download an appropriate OSM map for the area you wish to travel in. Some are routable too. Just be aware that the free version of Locus Maps is being deprecated, and the new version is subscription-based.

Good luck with whatever you decide!