Demo app: features in readme

demo-app/README.md

@@ -9,8 +9,58 @@ a quick and dirty example of how to get the agent initialized.
 
 ## Features
 
-* TBD
+The OpenTelemetry Android Demo App currently supports the following features:
 
+* Android Activity Lifecycle Monitoring
+  - Automatically captures spans for key lifecycle events:
+    - Created: Includes `onCreate`, `onStart`, `onResume`,
+    - Paused: Includes `onPause`,
+    - Stopped: Includes `onStop`,
+    - Destroyed: Includes `onDestroy`.
+  - This covers the entire Activity lifecycle, providing detailed insights into each phase.
+
+* Fragment Lifecycle Monitoring
+  - Automatically captures spans for key lifecycle events:
+    - Attached: `onAttach` (fragment attached to context),
+    - Created: `onCreate`,
+    - View Created: `onViewCreated` (UI created),
+    - Started: `onStart`,
+    - Resumed: `onResume` (fragment active),
+    - Paused: `onPause`,
+    - Stopped: `onStop`,
+    - View Destroyed: `onDestroyView` (UI removed),
+    - Destroyed: `onDestroy`,
+    - Detached: `onDetach` (fragment disconnected).
+  - Provides detailed insights into each lifecycle phase.
+  - Can be observed in the "About OpenTelemetry Android" activity, entered via "Learn more" on the main screen.
+
+* ANR Detection
+  - Automatically detects and reports ANRs in the app.
+  - ANR events are captured as spans with detailed stack traces, providing insights into the exact operations that caused the ANR.
+  - The span includes key attributes such as `screen.name`, `session.id`, and network information to assist in diagnosing the issue.
+  - Note: The app currently does not have any features designed to intentionally trigger an ANR.
+
+* Slow Render Detection
+  - Automatically detects instances of slow rendering within the app.
+  - Slow render events are captured as spans, providing information on when and where rendering delays occurred.
+  - The span includes attributes such as `activity.name`, `screen.name`, `count`, and network details to help diagnose performance issues.
+  - Note: The app currently does not have any features designed to intentionally trigger slow rendering.
+
+* Manual Instrumentation
+  - Provides access to the OpenTelemetry APIs for manual instrumentation, allowing developers to create custom spans and events as needed.
+  - Note: The only manual instrumentation that has been added to the demo app so far is an event after clicking on the OpenTelemetry logo.
+
+### Known Gaps
+As of now, there are a few areas where the instrumentation might not be comprehensive:
+
+* Crash Reporting  
+App crashes are automatically reported, but the app currently does not include any features that intentionally trigger crashes.
+
+* HTTP Client Instrumentation  
+OpenTelemetry Android supports automatic instrumentation for HTTP client libraries. This feature captures spans for HTTP requests with details. However, the demo app does not currently demonstrate this feature as it doesn't make any network requests.
+
+* Disk Buffering  
+Disk buffering is enabled in the app, allowing telemetry data to be temporarily stored on disk when the network is unavailable. Although this feature is configured, it isn't actively demonstrated due to the absence of network activity.
 
 ## How to use