diff --git a/README.md b/README.md
index 9dbfe11..cb3a920 100644
--- a/README.md
+++ b/README.md
@@ -1,4 +1,56 @@
 [![JetBrains Research](https://jb.gg/badges/research.svg)](https://confluence.jetbrains.com/display/ALL/JetBrains+on+GitHub)
 
 # DataForge-control
-Data acquisition framework based on DataForge
+
+DataForge-control is a data acquisition framework (work in progress). It is
+based on DataForge, a software framework for automated data processing. 
+This repository contains a prototype of API and simple implementation 
+of a slow control system, including a demo.
+
+DataForge-control uses some concepts and modules of DataForge, 
+such as `Meta` (immutable tree-like structure) and `MetaItem` (which 
+includes a scalar value, or a tree of values, easily convertable to/from JSON 
+if needed).  
+
+To learn more about DataForge, please consult the following URLs:
+ * [Kotlin multiplatform implementation of DataForge](https://github.com/mipt-npm/dataforge-core)  
+ * [DataForge documentation](http://npm.mipt.ru/dataforge/) 
+ * [Original implementation of DataForge](https://bitbucket.org/Altavir/dataforge/src/default/)
+
+DataForge-control is a [Kotlin-multiplatform](https://kotlinlang.org/docs/reference/multiplatform.html)
+application. Asynchronous operations are implemented with 
+[kotlinx.coroutines](https://github.com/Kotlin/kotlinx.coroutines) library.
+
+
+### Features
+Among other things, you can:
+- Describe devices and their properties. 
+- Collect data from devices and execute arbitrary actions supported by a device.
+- Property values can be cached in the system and requested from devices as needed, asynchronously.
+- Connect devices to event bus via bidirectional message flows.
+
+### `dataforge-control-core` module packages
+
+- `api` - defines API for device management. The main class here is 
+[`Device`](dataforge-control-core/src/commonMain/kotlin/hep/dataforge/control/api/Device.kt).
+Generally, a Device has Properties that can be read and written. Also, some Actions
+can optionally be applied on a device (may or may not affect properties). 
+
+- `base` - contains baseline `Device` implementation 
+[`DeviceBase`](dataforge-control-core/src/commonMain/kotlin/hep/dataforge/control/base/DeviceBase.kt) 
+and property implementation, including property asynchronous flows.
+
+- `controllers` - implements Message Controller that can be attached to the event bus, Message 
+and Property flows.
+
+### `demo` module
+
+The demo includes a simple mock device with a few properties changing as `sin` and `cos` of
+the current time. The device is configurable via a simple TornadoFX-based control panel. 
+You can run a demo by executing `application/run` Gradle task. 
+
+The graphs are displayed using [plotly.kt](https://github.com/mipt-npm/plotly.kt) library.
+
+Example view of a demo:
+
+![](docs/pictures/demo-view.png)
diff --git a/dataforge-control-core/src/commonMain/kotlin/hep/dataforge/control/api/Device.kt b/dataforge-control-core/src/commonMain/kotlin/hep/dataforge/control/api/Device.kt
index 0c5e2e8..448a4fc 100644
--- a/dataforge-control-core/src/commonMain/kotlin/hep/dataforge/control/api/Device.kt
+++ b/dataforge-control-core/src/commonMain/kotlin/hep/dataforge/control/api/Device.kt
@@ -6,6 +6,9 @@ import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.cancel
 import kotlinx.io.Closeable
 
+/**
+ *  General interface describing a managed Device
+ */
 interface Device: Closeable {
     /**
      * List of supported property descriptors
@@ -13,7 +16,8 @@ interface Device: Closeable {
     val propertyDescriptors: Collection<PropertyDescriptor>
 
     /**
-     * List of supported requests descriptors
+     * List of supported action descriptors. Action is a request to the device that
+     * may or may not change the properties
      */
     val actionDescriptors: Collection<ActionDescriptor>
 
@@ -30,12 +34,13 @@ interface Device: Closeable {
     fun registerListener(listener: DeviceListener, owner: Any? = listener)
 
     /**
-     * Remove all listeners belonging to specified owner
+     * Remove all listeners belonging to the specified owner
      */
-    fun removeListener(owner: Any?)
+    fun removeListeners(owner: Any?)
 
     /**
-     * Get the value of the property or throw error if property in not defined. Suspend if property value is not available
+     * Get the value of the property or throw error if property in not defined.
+     * Suspend if property value is not available
      */
     suspend fun getProperty(propertyName: String): MetaItem<*>
 
@@ -51,8 +56,8 @@ interface Device: Closeable {
     suspend fun setProperty(propertyName: String, value: MetaItem<*>)
 
     /**
-     * Send a request and suspend caller while request is being processed.
-     * Could return null if request does not return meaningful answer.
+     * Send an action request and suspend caller while request is being processed.
+     * Could return null if request does not return a meaningful answer.
      */
     suspend fun call(action: String, argument: MetaItem<*>? = null): MetaItem<*>?
 
diff --git a/dataforge-control-core/src/commonMain/kotlin/hep/dataforge/control/api/DeviceHub.kt b/dataforge-control-core/src/commonMain/kotlin/hep/dataforge/control/api/DeviceHub.kt
index 9e285b6..46958c2 100644
--- a/dataforge-control-core/src/commonMain/kotlin/hep/dataforge/control/api/DeviceHub.kt
+++ b/dataforge-control-core/src/commonMain/kotlin/hep/dataforge/control/api/DeviceHub.kt
@@ -18,6 +18,6 @@ suspend fun DeviceHub.setProperty(deviceName: String, propertyName: String, valu
         .setProperty(propertyName, value)
 }
 
-suspend fun DeviceHub.request(deviceName: String, command: String, argument: MetaItem<*>?): MetaItem<*>? =
+suspend fun DeviceHub.call(deviceName: String, command: String, argument: MetaItem<*>?): MetaItem<*>? =
     (getDevice(deviceName) ?: error("Device with name $deviceName not found in the hub"))
         .call(command, argument)
\ No newline at end of file
diff --git a/dataforge-control-core/src/commonMain/kotlin/hep/dataforge/control/api/DeviceListener.kt b/dataforge-control-core/src/commonMain/kotlin/hep/dataforge/control/api/DeviceListener.kt
index e0a0f59..c5e2f06 100644
--- a/dataforge-control-core/src/commonMain/kotlin/hep/dataforge/control/api/DeviceListener.kt
+++ b/dataforge-control-core/src/commonMain/kotlin/hep/dataforge/control/api/DeviceListener.kt
@@ -2,6 +2,11 @@ package hep.dataforge.control.api
 
 import hep.dataforge.meta.MetaItem
 
+/**
+ * PropertyChangeListener Interface
+ * [value] is a new value that property has after a change; null is for invalid state.
+ */
+interface PropertyChangeListener {
 interface DeviceListener {
     fun propertyChanged(propertyName: String, value: MetaItem<*>?)
     //TODO add general message listener method
diff --git a/dataforge-control-core/src/commonMain/kotlin/hep/dataforge/control/base/DeviceBase.kt b/dataforge-control-core/src/commonMain/kotlin/hep/dataforge/control/base/DeviceBase.kt
index c2fdc94..79c06a5 100644
--- a/dataforge-control-core/src/commonMain/kotlin/hep/dataforge/control/base/DeviceBase.kt
+++ b/dataforge-control-core/src/commonMain/kotlin/hep/dataforge/control/base/DeviceBase.kt
@@ -6,6 +6,9 @@ import hep.dataforge.control.api.DeviceListener
 import hep.dataforge.control.api.PropertyDescriptor
 import hep.dataforge.meta.MetaItem
 
+/**
+ * Baseline implementation of [Device] interface
+ */
 abstract class DeviceBase : Device {
     private val properties = HashMap<String, ReadOnlyDeviceProperty>()
     private val actions = HashMap<String, Action>()
@@ -16,7 +19,7 @@ abstract class DeviceBase : Device {
         listeners.add(owner to listener)
     }
 
-    override fun removeListener(owner: Any?) {
+    override fun removeListeners(owner: Any?) {
         listeners.removeAll { it.first == owner }
     }
 
diff --git a/dataforge-control-core/src/commonMain/kotlin/hep/dataforge/control/controlers/DeviceMessage.kt b/dataforge-control-core/src/commonMain/kotlin/hep/dataforge/control/controllers/DeviceMessage.kt
similarity index 98%
rename from dataforge-control-core/src/commonMain/kotlin/hep/dataforge/control/controlers/DeviceMessage.kt
rename to dataforge-control-core/src/commonMain/kotlin/hep/dataforge/control/controllers/DeviceMessage.kt
index 0adf5ab..9a5aaa5 100644
--- a/dataforge-control-core/src/commonMain/kotlin/hep/dataforge/control/controlers/DeviceMessage.kt
+++ b/dataforge-control-core/src/commonMain/kotlin/hep/dataforge/control/controllers/DeviceMessage.kt
@@ -1,4 +1,4 @@
-package hep.dataforge.control.controlers
+package hep.dataforge.control.controllers
 
 import hep.dataforge.control.controlers.DeviceMessage.Companion.PAYLOAD_VALUE_KEY
 import hep.dataforge.meta.*
diff --git a/dataforge-control-core/src/commonMain/kotlin/hep/dataforge/control/controlers/MessageController.kt b/dataforge-control-core/src/commonMain/kotlin/hep/dataforge/control/controllers/MessageController.kt
similarity index 95%
rename from dataforge-control-core/src/commonMain/kotlin/hep/dataforge/control/controlers/MessageController.kt
rename to dataforge-control-core/src/commonMain/kotlin/hep/dataforge/control/controllers/MessageController.kt
index aa4421a..2c4a105 100644
--- a/dataforge-control-core/src/commonMain/kotlin/hep/dataforge/control/controlers/MessageController.kt
+++ b/dataforge-control-core/src/commonMain/kotlin/hep/dataforge/control/controllers/MessageController.kt
@@ -1,8 +1,10 @@
-package hep.dataforge.control.controlers
+package hep.dataforge.control.controllers
 
 import hep.dataforge.control.api.Device
 import hep.dataforge.control.api.DeviceListener
 import hep.dataforge.control.controlers.DeviceMessage.Companion.PROPERTY_CHANGED_ACTION
+import hep.dataforge.control.api.PropertyChangeListener
+import hep.dataforge.control.controllers.DevicePropertyMessage.Companion.PROPERTY_CHANGED_ACTION
 import hep.dataforge.io.Envelope
 import hep.dataforge.io.Responder
 import hep.dataforge.io.SimpleEnvelope
diff --git a/dataforge-control-core/src/commonMain/kotlin/hep/dataforge/control/controllers/MessageFlow.kt b/dataforge-control-core/src/commonMain/kotlin/hep/dataforge/control/controllers/MessageFlow.kt
new file mode 100644
index 0000000..e69de29
diff --git a/dataforge-control-core/src/commonMain/kotlin/hep/dataforge/control/controlers/PropertyFlow.kt b/dataforge-control-core/src/commonMain/kotlin/hep/dataforge/control/controllers/PropertyFlow.kt
similarity index 86%
rename from dataforge-control-core/src/commonMain/kotlin/hep/dataforge/control/controlers/PropertyFlow.kt
rename to dataforge-control-core/src/commonMain/kotlin/hep/dataforge/control/controllers/PropertyFlow.kt
index 8a3d82e..ed45c53 100644
--- a/dataforge-control-core/src/commonMain/kotlin/hep/dataforge/control/controlers/PropertyFlow.kt
+++ b/dataforge-control-core/src/commonMain/kotlin/hep/dataforge/control/controllers/PropertyFlow.kt
@@ -1,4 +1,4 @@
-package hep.dataforge.control.controlers
+package hep.dataforge.control.controllers
 
 import hep.dataforge.control.api.Device
 import hep.dataforge.control.api.DeviceListener
@@ -21,8 +21,8 @@ suspend fun Device.flowValues(): Flow<Pair<String, MetaItem<*>>> = callbackFlow
             }
         }
     }
-    registerListener(listener, listener)
+    registerListener(listener)
     awaitClose {
-        removeListener(listener)
+        removeListeners(listener)
     }
 }
\ No newline at end of file
diff --git a/dataforge-control-core/src/commonMain/kotlin/hep/dataforge/control/controlers/delegateMappers.kt b/dataforge-control-core/src/commonMain/kotlin/hep/dataforge/control/controllers/delegateMappers.kt
similarity index 91%
rename from dataforge-control-core/src/commonMain/kotlin/hep/dataforge/control/controlers/delegateMappers.kt
rename to dataforge-control-core/src/commonMain/kotlin/hep/dataforge/control/controllers/delegateMappers.kt
index 1827d94..d80ceeb 100644
--- a/dataforge-control-core/src/commonMain/kotlin/hep/dataforge/control/controlers/delegateMappers.kt
+++ b/dataforge-control-core/src/commonMain/kotlin/hep/dataforge/control/controllers/delegateMappers.kt
@@ -1,4 +1,4 @@
-package hep.dataforge.control.controlers
+package hep.dataforge.control.controllers
 
 import hep.dataforge.control.base.DeviceProperty
 import hep.dataforge.control.base.ReadOnlyDeviceProperty
diff --git a/demo/build.gradle.kts b/demo/build.gradle.kts
index 6c5eeaa..1cea9ce 100644
--- a/demo/build.gradle.kts
+++ b/demo/build.gradle.kts
@@ -1,6 +1,7 @@
 plugins {
     kotlin("jvm") version "1.3.72"
     id("org.openjfx.javafxplugin") version "0.0.8"
+    `application`
 }
 
 val plotlyVersion: String by rootProject.extra
@@ -31,4 +32,8 @@ tasks.withType<org.jetbrains.kotlin.gradle.tasks.KotlinCompile>().configureEach
 javafx{
     version = "14"
     modules("javafx.controls")
+}
+
+application{
+    mainClassName = "hep.dataforge.control.demo.DemoControllerViewKt"
 }
\ No newline at end of file
diff --git a/demo/src/main/kotlin/hep/dataforge/control/demo/DemoDevice.kt b/demo/src/main/kotlin/hep/dataforge/control/demo/DemoDevice.kt
index 3d871e0..52b4c56 100644
--- a/demo/src/main/kotlin/hep/dataforge/control/demo/DemoDevice.kt
+++ b/demo/src/main/kotlin/hep/dataforge/control/demo/DemoDevice.kt
@@ -1,7 +1,7 @@
 package hep.dataforge.control.demo
 
 import hep.dataforge.control.base.*
-import hep.dataforge.control.controlers.double
+import hep.dataforge.control.controllers.double
 import hep.dataforge.values.asValue
 import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.GlobalScope
@@ -26,10 +26,6 @@ class DemoDevice(parentScope: CoroutineScope = GlobalScope) : DeviceBase() {
     val timeScale: IsolatedDeviceProperty by writingVirtual(5000.0.asValue())
     var timeScaleValue by timeScale.double()
 
-    val resetScale: Action by action {
-        timeScaleValue = 5000.0
-    }
-
     val sinScale by writingVirtual(1.0.asValue())
     var sinScaleValue by sinScale.double()
     val sin by readingNumber {
@@ -51,6 +47,13 @@ class DemoDevice(parentScope: CoroutineScope = GlobalScope) : DeviceBase() {
         "y" put cos(time.toEpochMilli().toDouble() / timeScaleValue)*cosScaleValue
     }
 
+
+    val resetScale: Action by action {
+        timeScaleValue = 5000.0
+        sinScaleValue = 1.0
+        cosScaleValue = 1.0
+    }
+
     init {
         sin.readEvery(0.2.seconds)
         cos.readEvery(0.2.seconds)
diff --git a/docs/pictures/demo-view.png b/docs/pictures/demo-view.png
new file mode 100644
index 0000000..b7df1eb
Binary files /dev/null and b/docs/pictures/demo-view.png differ