Castle isn't in the iOS App Store, so if you want to use it on an iPhone, you need to build it yourself. This requires a Mac with Xcode. We might be able to create an easier way to get Castle for iPhone later, but this is the way things are now.
Here are the steps to get it onto your phone.
You can get Xcode from the Mac App Store. And if you already have it, make sure its up-to-date. If you don't have a Mac, you can't get Castle onto your iPhone just yet. Sorry.
Installing Xcode can take an hour or so.
Homebrew is a package manager macOS. Mostly it gets used for things like command line programming tools (stuff you wouldn't get through the Mac App Store). We'll use it to install some tools that are required to build Castle.
You can do this by opening a terminal window (you can do ⌘-Space and then type "terminal" and then return to open Terminal) and then running the command:
/usr/bin/ruby -e "$(curl -fsSL [<https://raw.githubusercontent.com/Homebrew/install/master/install>](<https://raw.githubusercontent.com/Homebrew/install/master/install>))"
If you already have the most recent version of node installed or you use something like nvm then you can skip this step.
Otherwise, run brew install node at the command line in your terminal.
If you have git installed already, you can skip this step. You can test that by running git --version from the command line. If you see something that says "command not found" then you need to install git. If you see a version number, then you're already all set.
If you need to, you can install git by running brew install git at the command line.
In the terminal, run
git clone <https://github.com/castle-games/castle-client.git>
You should see some output like this
ccheever@Charlies-iMac:~$git clone <https://github.com/castle-games/castle-client.git>
Cloning into 'castle-client'...
remote: Enumerating objects: 55, done.
remote: Counting objects: 100% (55/55), done.
remote: Compressing objects: 100% (45/45), done.
remote: Total 92681 (delta 16), reused 35 (delta 10), pack-reused 92626
Receiving objects: 100% (92681/92681), 908.04 MiB | 16.21 MiB/s, done.
Resolving deltas: 100% (46934/46934), done.
Updating files: 100% (55487/55487), done.
Filtering content: 100% (5/5), 564.75 MiB | 15.60 MiB/s, done.
ccheever@Charlies-iMac:~$