Update demo-apps-ios.md (#9986)

cc @mergennachin @byjlw

Co-authored-by: Anthony Shoumikhin <[email protected]>

Author: pytorchbot

docs/source/demo-apps-ios.md

@@ -1 +1,141 @@
-```{include} ../../examples/demo-apps/apple_ios/ExecuTorchDemo/README.md
+# Building an ExecuTorch iOS Demo App
+
+Welcome to the tutorial on setting up the ExecuTorch iOS Demo App!
+
+This app uses the
+[MobileNet v3](https://pytorch.org/vision/main/models/mobilenetv3.html) model to
+process live camera images leveraging three different backends:
+[XNNPACK](https://github.com/google/XNNPACK),
+[Core ML](https://developer.apple.com/documentation/coreml) and
+[Metal Performance Shaders (MPS)](https://developer.apple.com/documentation/metalperformanceshaders)
+(Xcode 15+ and iOS 17+ only).
+
+![](_static/img/demo_ios_app.jpg)
+
+## Prerequisites
+
+Before we start, make sure you have the following tools installed:
+
+### 1. Xcode 15 and Command Line Tools
+
+Install Xcode 15 from the
+[Mac App Store](https://apps.apple.com/app/xcode/id497799835) and then install
+the Command Line Tools using the terminal:
+
+```bash
+xcode-select --install
+```
+
+### 2. Python 3.10+
+
+Python 3.10 or above, along with `pip`, should be pre-installed on MacOS 13.5+.
+If needed, [download Python](https://www.python.org/downloads/macos/) and
+install it. Verify the Python and pip versions using these commands:
+
+```bash
+which python3 pip
+python3 --version
+pip --version
+```
+
+### 3. Getting Started Tutorial
+
+Follow the [Setting Up ExecuTorch](https://pytorch.org/executorch/stable/getting-started-setup)
+tutorial to configure the basic environment:
+
+```bash
+git clone -b viable/strict https://github.com/pytorch/executorch.git && cd executorch
+
+python3 -m venv .venv && source .venv/bin/activate && pip install --upgrade pip
+
+./install_executorch.sh
+```
+
+### 4. Clone the Demo App
+
+```bash
+git clone --depth 1 https://github.com/pytorch-labs/executorch-examples.git
+```
+
+### 5. Backend Dependencies
+
+Also, follow the corresponding sections from [Core ML](https://pytorch.org/executorch/stable/build-run-coreml) and
+[MPS](https://pytorch.org/executorch/stable/build-run-mps) tutorials to install additional dependencies for those
+backends:
+
+```bash
+./backends/apple/coreml/scripts/install_requirements.sh
+
+./backends/apple/mps/install_requirements.sh
+```
+
+## Models and Labels
+
+Now, let's move on to exporting and bundling the MobileNet v3 model.
+
+### 1. Export Model
+
+Export the MobileNet v3 model with Core ML, MPS and XNNPACK backends, and move
+the exported model to a specific location where the Demo App will pick them up:
+
+```bash
+MODEL_NAME="mv3"
+
+python3 -m examples.portable.scripts.export --model_name="$MODEL_NAME"
+python3 -m examples.apple.coreml.scripts.export --model_name="$MODEL_NAME"
+python3 -m examples.apple.mps.scripts.mps_example --model_name="$MODEL_NAME"
+python3 -m examples.xnnpack.aot_compiler --model_name="$MODEL_NAME" --delegate
+
+APP_PATH="executorch-examples/apple/ExecuTorchDemo/ExecuTorchDemo"
+
+mkdir -p "$APP_PATH/Resources/Models/MobileNet/"
+mv $MODEL_NAME*.pte "$APP_PATH/Resources/Models/MobileNet/"
+```
+
+### 2. Download Labels
+
+Download the MobileNet model labels required for image classification:
+
+```bash
+curl https://raw.githubusercontent.com/pytorch/hub/master/imagenet_classes.txt \
+  -o "$APP_PATH/Resources/Models/MobileNet/imagenet_classes.txt"
+```
+
+## Final Steps
+
+We're almost done! Now, we just need to open the project in Xcode, run the
+tests, and finally run the app.
+
+### 1. Open Project in Xcode
+
+Double-click on the project file under `executorch-examples/apple/ExecuTorchDemo` or run the command:
+
+```bash
+open $APP_PATH.xcodeproj
+```
+
+### 2. Run Tests
+
+You can run tests on Simulaltor directly in Xcode with `Cmd + U` or use the
+command line:
+
+```bash
+xcrun simctl create executorch "iPhone 15"
+xcodebuild clean test \
+     -project $APP_PATH.xcodeproj \
+     -scheme App \
+     -destination name=executorch
+xcrun simctl delete executorch
+```
+
+### 3. Run App
+
+Finally, connect the device, set up Code Signing in Xcode, and then run the app
+using `Cmd + R`. Try installing a Release build for better performance.
+
+Congratulations! You've successfully set up the ExecuTorch iOS Demo App. Now,
+you can explore and enjoy the power of ExecuTorch on your iOS device!
+
+Learn more about integrating and running [ExecuTorch on Apple](https://pytorch.org/executorch/stable/apple-runtime) platforms.
+
+![](_static/img/demo_ios_xcode.jpg)