add android functions example

Author: b3b

README.rst

@@ -27,6 +27,7 @@ PythonHere
 - *Here* is a server part with the GUI interface. It could be Android, Raspberry Pi, some other remote device that being debugged.
 - And *%there* is a client - Jupyter magic command to run code interactively on remote device.
 
+Project documentation: https://herethere.me
 
 .. |jupyter| image:: https://raw.githubusercontent.com/b3b/pythonhere/master/docs/left_jupyter.png
    :align: middle
@@ -44,8 +45,6 @@ PythonHere
    * - |jupyter|
      - |android|
 
-Project documentation: https://herethere.me
-
 
 Install on Android
 ------------------

examples/android.md

@@ -0,0 +1,56 @@
+---
+jupyter:
+  jupytext:
+    text_representation:
+      extension: .md
+      format_name: markdown
+      format_version: '1.2'
+      jupytext_version: 1.7.1
+  kernelspec:
+    display_name: Python 3
+    language: python
+    name: python3
+---
+
+# Android functions
+Android platform features could be used with [PyJNIus](https://github.com/kivy/pyjnius) and [Plyer](https://github.com/kivy/plyer) libraries.
+
+```python
+%load_ext pythonhere
+%connect-there
+```
+
+## Send SMS
+
+
+### Request SEND_SMS runtime permission
+
+```python
+%there -bl 1 log
+```
+
+```python
+%%there
+from kivy.logger import Logger
+from android.permissions import Permission, check_permission, request_permission
+
+def permissions_callback(permissions, grant_results):
+    if permissions and all(grant_results):
+        Logger.info("Runtime permissions: granted")
+    else:
+        Logger.error("Runtime permissions: not granted")
+
+permission = Permission.SEND_SMS
+if check_permission(permission):
+    print(f"{permission} is already granted")
+else:
+    request_permission(permission, callback=permissions_callback)
+```
+
+### Send message with Plyer
+
+```python
+%%there
+import plyer
+plyer.sms.send(recipient=" ", message="Hey!")
+```