Below are some screenshots (with the help button pushed, that adds the yellow description boxes) that show you some of the apps features, but they are so extensive that I would recommend that you check out their numerous Youtube Videos if you want to learn more before buying the app. Right now, the app costs $19.99, but the are going to increase the price after the initial period.
I may have a more thorough review down the road, but out of the gate, I am very pleased with this app! It has most every feature I use in Photoshop, but it will take some time to get used to it since I am much more familiar with Photoshop. Hopefully, this will help get Adobe to actually create a comparable app for the iPad. At this point it is unforgivable that Adobe has, for the most part, ignored this very popular platform, To give you an idea just how popular the iPad is, last year, which was considered a down year for the iPad, Apple sold more iPads than Dell sold of all their computers put together. In other words, it was near the number of all business laptops sold. To continue to ignore this market is a mistake.
Affinity Photo is smart. With it being (arguably?) the only pro level photo app on the iPad, it could actually move people away from Creative Cloud and to the Affinity computer app. I am not ready to make that step because I am used to the workflow, but if I was just starting out, I might look for products that don't require a monthly subscription that do the same thing as Creative Cloud, especially if I preferred editing photos with the iPad rather than a PC.