Adds new flutter module, reconfigures Android/iOS sample (#144)

experimental/add_to_app/README.md

@@ -5,7 +5,7 @@ and the latest version of CocoaPods. See the [README](../README.md) in the
 `experimental` directory for details.***
 
 This directory contains a bunch of Android and iOS projects that each import
-a standalone Flutter module called `example_module`.
+a standalone Flutter module called `flutter_module`.
 
 ## Goals for this sample
 
@@ -13,42 +13,63 @@ a standalone Flutter module called `example_module`.
 
 ## The important bits
 
-### `example_module`
+### Flutter modules
 
-This is the Flutter module that'll be added to all the individual projects
-in the `add_to_app` folder.
+There are two Flutter modules included in the codebase:
 
-The first time you download this repo, you need to first resolve this
-module's dependencies by running:
+* `flutter_module` displays the dimensions of the screen, a button that
+  increments a simple counter, and an optional exit button.
+* `flutter_module_using_plugin` does everything `flutter_module` does, and adds
+  another button that will save the counter's value to a file using the
+  [`path_provider`](https://pub.dev/packages/path_povider) Flutter plugin.
+
+Before running any of the Android or iOS apps included in this sample project,
+you first need to resolve the Flutter modules' depencies. Do so by running this
+command from within the `flutter_module` and `flutter_module_using_plugin`
+directories:
 
 ```bash
-cd example_module
 flutter packages get
 ```
 
-### `SimpleAndroidApp`
+### Android and iOS applications
 
-An Android application that imports `example_module` and uses it to display
-a `FlutterActivity` containing widgets from the module. This project brings
-in the Flutter module's Android host wrapper as a gradle sub-module.
+In addition to the Flutter modules, this repo also includes a number of
+Android and iOS applications that demonstrate different ways of importing
+them.
 
-To run, open the SimpleAndroidApp folder in Android Studio and press the run
-button.
+The Android apps are ready to run once you've completed the
+`flutter packages get` commands listed above. The iOS apps use CocoaPods,
+so you need to run this command to install the dependencies listed in their
+Podfiles prior to running them the first time.
 
-### `SimpleIOSExample`
-
-An iOS application that imports `example_module` and uses it to display
-a `FlutterViewController` containing widgets from the module. This project
-uses CocoaPods, so prior to running it for the first time, use this command
-to set up the workspace file:
+This should be done in the individual project directories themselves. For
+example, prior to running `ios_fullscreen` for the first time, you need to run
+these commands:
 
 ```bash
-cd ../SimpleIOSExample
+cd ios_fullscreen
 pod install
 ```
 
-Then open SimpleIOSExample/SimpleIOSExample.xcworkspace with Xcode. This
-workspace will have the Flutter module linked in as a dependent CocoaPod.
+Once that command is complete, you'll find an `xcworkspace` file in the project
+directories with the correct Flutter module (and any other dependencies)
+included. Open that workspace file, and the app is ready to build and run.
+
+### `android_fullscreen` and `ios_fullscreen`
+
+These apps showcase a relatively straightforward integration of
+`flutter_module`:
+
+* The Flutter module is built along with the app when the app is built.
+* The Flutter engine is warmed up at app launch.
+* The Flutter view is presented with a full-screen Activity or
+  UIViewController.
+* The Flutter view is a navigational leaf node; it does not launch any new,
+  native Activities or UIViewControllers in response to user actions.
+
+If you are new to Flutter's add-to-app APIs, these projects are a great place
+to begin learning how to use them.
 
 ## Questions/issues