diff --git a/README.md b/README.md
index 960d0b6..d783dc7 100644
--- a/README.md
+++ b/README.md
@@ -11,11 +11,20 @@
 * Auto stop tomato and break.
 * Tomatoes counter.
 * Switch to tomato when user press stop.
+* Execute custom commands when the timer is started, stopped or changed state.
 
 ## Requirements
 
 * Python>=3.6
 * PyQt5
+* qt5-multimedia package
+
+## Tested on
+
+* Arch Linux
+* KDE5
+* FullHD Display
+* Python 3.7, 3.8
 
 ## Installing
 
@@ -25,10 +34,68 @@ CherryTomato can be used without installation (by executing `main.py`). However,
 
 ### Arch Linux
 
-Also you can install CherryTomato from AUR:
+Also you can install [CherryTomato from AUR](https://aur.archlinux.org/packages/cherrytomato):
 
 `yaourt -S cherrytomato`
 
+## Execute custom commands
+
+You can specify custom commands that will be triggered on some events like the timer is started, stopped or changed state.
+
+Commands executed with python `subprocess.Popen` without `shell=True` option. It means that you can't use pipes or redirect output. You can read more about this in [subprocess documentation](https://docs.python.org/3/library/subprocess.html#subprocess.Popen).
+
+But if you need pipes and other shell features you can write your own script, place it in filesystem and execute from CherryTomato.
+
+Also, you can pass some info about timer to your custom commands with macros:
+
+* `{tomatoes}` - number of completed tomatoes
+* `{state}` - current timer state ("tomato", "break" or "long_break")
+
+Examples you can see on screenshot.
+
+`/opt/scripts/test.sh` from screenshot example:
+
+```shell script
+#!/bin/bash
+
+tomatoes=$1
+state=$2
+
+if [ $tomatoes -gt 10 ]
+then
+    # ...
+    # greater than 10 logic
+    # ...
+else
+    # ...
+    # lesser than 10 logic
+    # ...
+fi
+
+
+if [ $state = "tomato" ]
+then
+    # ...
+    # is tomato state logic
+    # ...
+elif [ $state = "break" ]
+then
+    # ...
+    # is break state logic
+    # ...
+elif [ $state = "long_break" ]
+then
+    # ...
+    # is long break state logic
+    # ...
+fi
+```
+
+Another example - you can simply play and pause music on Spotify with commands:
+
+`dbus-send --print-reply --dest=org.mpris.MediaPlayer2.spotify /org/mpris/MediaPlayer2 org.mpris.MediaPlayer2.Player.Play`
+
+`dbus-send --print-reply --dest=org.mpris.MediaPlayer2.spotify /org/mpris/MediaPlayer2 org.mpris.MediaPlayer2.Player.Pause`
 
 ## Credits
 
diff --git a/assets/screenshot.png b/assets/screenshot.png
index 237bb40..3441ded 100644
Binary files a/assets/screenshot.png and b/assets/screenshot.png differ