Just an FYI,
During a past Gunsite XLR Class, two different shooters, simultaneously running a Nomad w/ FFS and an iPhone with an App (me included) saw the App work great until we went past 1500m then the App would mysteriously go off by a full Mil until we reset it. Did it more than once on both units. Now, not all Apps are created equal, and they tend to update and fix them all the time, so it could have just been that build, but something to consider. Different builds, versions, etc, can have issues because the Apps are not very robust.
If you are shooting far, you are spending a good deal of money, so why skimp on the software. A Nomad with either Field Firing Solution or Patagonia ColdBore is the way to go. (I have both loaded on one unit) If you want to save money, just get a cheaper unit like a Trimble Recon and run ColdBore, you'll save about half the cost of a Nomad, but still have all the features and function, plus a desktop companion that will allow you to speak and update your mobile device. In my mind that is the only way to compromise when shooting past 1000 yards, by getting a Recon or equivalent unit and sticking with CB1. The results will be much more secure than using an App...
I use Apps for reference and inside 1k, but anything else, they are really just a placeholder for a real ballistic computer. Personally I am not a fan of how Point Mass handles information, it is very biased and tends to punish people for not knowing everything they should, or using the wrong G Model. Where both FFS and CB1 handle things much better, and are not dependent on picking the right drag model, they don't care which you use. (In fact FFS only uses G1)