Add comments explaining analytics usage

react-native/RealmAnalytics.h

@@ -2,6 +2,43 @@
  * Proprietary and Confidential
  */
 
+// Asynchronously submits build information to Realm if running in an iOS
+// simulator or on OS X if a debugger is attached. Does nothing if running on an
+// iOS / watchOS device or if a debugger is *not* attached.
+//
+// To be clear: this does *not* run when your app is in production or on
+// your end-user’s devices; it will only run in the simulator or when a debugger
+// is attached.
+//
+// Why are we doing this? In short, because it helps us build a better product
+// for you. None of the data personally identifies you, your employer or your
+// app, but it *will* help us understand what language you use, what iOS
+// versions you target, etc. Having this info will help prioritizing our time,
+// adding new features and deprecating old features. Collecting an anonymized
+// bundle & anonymized MAC is the only way for us to count actual usage of the
+// other metrics accurately. If we don’t have a way to deduplicate the info
+// reported, it will be useless, as a single developer building their Swift app
+// 10 times would report 10 times more than a single Objective-C developer that
+// only builds once, making the data all but useless.
+// No one likes sharing data unless it’s necessary, we get it, and we’ve
+// debated adding this for a long long time. Since Realm is a free product
+// without an email signup, we feel this is a necessary step so we can collect
+// relevant data to build a better product for you. If you truly, absolutely
+// feel compelled to not send this data back to Realm, then you can set an env
+// variable named REALM_DISABLE_ANALYTICS. Since Realm is free we believe
+// letting these analytics run is a small price to pay for the product & support
+// we give you.
+//
+// Currently the following information is reported:
+// - What kind of JavaScript framework is being used (e.g. React Native).
+// - What version of Realm is being used, and from which language (obj-c or Swift).
+// - What version of OS X it's running on (in case Xcode aggressively drops
+//   support for older versions again, we need to know what we need to support).
+// - The minimum iOS/OS X version that the application is targeting (again, to
+//   help us decide what versions we need to support).
+// - An anonymous MAC address and bundle ID to aggregate the other information on.
+// - What version of Swift is being used (if applicable).
+
 #import <Foundation/Foundation.h>
 
 #ifdef __cplusplus

react-native/RealmAnalytics.mm

@@ -2,6 +2,43 @@
  * Proprietary and Confidential
  */
 
+// Asynchronously submits build information to Realm if running in an iOS
+// simulator or on OS X if a debugger is attached. Does nothing if running on an
+// iOS / watchOS device or if a debugger is *not* attached.
+//
+// To be clear: this does *not* run when your app is in production or on
+// your end-user’s devices; it will only run in the simulator or when a debugger
+// is attached.
+//
+// Why are we doing this? In short, because it helps us build a better product
+// for you. None of the data personally identifies you, your employer or your
+// app, but it *will* help us understand what language you use, what iOS
+// versions you target, etc. Having this info will help prioritizing our time,
+// adding new features and deprecating old features. Collecting an anonymized
+// bundle & anonymized MAC is the only way for us to count actual usage of the
+// other metrics accurately. If we don’t have a way to deduplicate the info
+// reported, it will be useless, as a single developer building their Swift app
+// 10 times would report 10 times more than a single Objective-C developer that
+// only builds once, making the data all but useless.
+// No one likes sharing data unless it’s necessary, we get it, and we’ve
+// debated adding this for a long long time. Since Realm is a free product
+// without an email signup, we feel this is a necessary step so we can collect
+// relevant data to build a better product for you. If you truly, absolutely
+// feel compelled to not send this data back to Realm, then you can set an env
+// variable named REALM_DISABLE_ANALYTICS. Since Realm is free we believe
+// letting these analytics run is a small price to pay for the product & support
+// we give you.
+//
+// Currently the following information is reported:
+// - What kind of JavaScript framework is being used (e.g. React Native).
+// - What version of Realm is being used, and from which language (obj-c or Swift).
+// - What version of OS X it's running on (in case Xcode aggressively drops
+//   support for older versions again, we need to know what we need to support).
+// - The minimum iOS/OS X version that the application is targeting (again, to
+//   help us decide what versions we need to support).
+// - An anonymous MAC address and bundle ID to aggregate the other information on.
+// - What version of Swift is being used (if applicable).
+
 #import "RealmAnalytics.h"
 
 #if TARGET_IPHONE_SIMULATOR || TARGET_OS_MAC

react-native/android/src/main/java/io/realm/react/RealmAnalytics.java

@@ -41,6 +41,7 @@ import java.util.Set;
 // better product for you.
 //
 // Currently the following information is reported:
+// - What kind of JavaScript framework is being used (e.g. React Native)
 // - What version of Realm is being used
 // - What OS you are running on
 // - An anonymized MAC address and bundle ID to aggregate the other information on.