Back in the day before ballistic apps, I used the JBM web site. Pretty sure that was from the late 1990s, even before laser range finders were commonly available. JBM is free and pretty reliable.
Apps I have used are Strelok Pro, Applied Ballistics and Hornady 4DOF. The Hornady app is free to download and use. It has a table of Hornady data preloaded, and you can manually add other ballets. I found some differences in results with the 4DOF app vs the other apps I use, and since I am more invested in other apps, I didnt really persevere with it.
I have used Strelok and AB a lot more. I use Strelok the most because I find the interface easiest to use. AB is very good too, but I find its a lot harder to read the data off the app in bright sunlight. Just for that reason, I find I use Strelok the most.