diff --git a/db/create.py b/db/create.py
index 879fe51..1cb7968 100644
--- a/db/create.py
+++ b/db/create.py
@@ -1,5 +1,46 @@
+"""
+Create database file and tables if not exists.
+::
+
+    +--------------+
+    |services      |                 +---------------+
+    +--------------+                 |notifications  |
+    |service_id    |<--------+       +---------------+
+    |token         |         |       |notification_id|
+    |name          |         +-------|service_id     |
+    |description   |                 |timestamp      |
+    |representation|                 |content_json   |
+    |by_request    |                 +---------------+
+    +--------------+
+
+* services table
+    * **service_id:**      service id
+                               *(integer primary key)*.
+    * **token:**           service token for access to api
+                               *(text, not null)*.
+    * **name:**            service name
+                               *(text, not null)*.
+    * **description:**     service description
+                               *(text with default value)*.
+    * **representation:**  how to display notification
+                               *(integer with 0 as default)*.
+    * **by_request:**      send notifications automatically or not
+                               *(integer with 0 as default)*.
+* notifications table
+    * **notification_id:** notification id
+                               *(integer primary key)*.
+    * **service_id:**      service id
+                               *(integer, not null, references to*
+                               *service_id in service table)*.
+    * **timestamp:**       UTC timestamp, example: **"2022-02-14T13:45:15Z"**
+                               *(text, not null)*.
+
+    * **content_json:**    content in json_format
+                               *(text, not null)*.
+"""
 import sqlite3
 
+
 CREATE_SERVICES_TABLE = '''CREATE TABLE IF NOT EXISTS services (
 service_id INTEGER PRIMARY KEY,
 token TEXT NOT NULL,
@@ -20,6 +61,12 @@ ON UPDATE CASCADE ON DELETE CASCADE
 
 
 def create_tables_if_not_exists(dbfile: str) -> None:
+    """
+    Create database file and tables if not exists.
+    *See module docstring*.
+
+    :param dbfile: path to database file.
+    """
     connection = sqlite3.connect(dbfile)
     cursor = connection.cursor()
     cursor.execute('PRAGMA foreign_keys=0')
diff --git a/start.py b/start.py
index 7e88d3c..996010f 100644
--- a/start.py
+++ b/start.py
@@ -3,10 +3,11 @@ import logging
 from aiohttp import web
 
 from config import config
+from telegram import telegram_bot, telegram_dispatcher
 import db
-from web import app
-
+from web import create_app
 
+app = create_app(telegram_bot, telegram_dispatcher, config)
 logging.basicConfig(level=logging.INFO)
 
 
diff --git a/web/__init__.py b/web/__init__.py
index 0e428a9..4e14062 100644
--- a/web/__init__.py
+++ b/web/__init__.py
@@ -1,34 +1,44 @@
 import logging
+from aiogram import Bot, Dispatcher
 from aiogram.dispatcher.webhook import configure_app
-from aiohttp import web
+from aiohttp.web import Application
 
-from config import config
-from telegram import telegram_bot, telegram_dispatcher
+from config import Config
 from .routes import routes, TELEGRAM_WEBHOOK_ROUTE
 
 
-TELEGRAM_WEBHOOK_URL = f'{config.base_url}{TELEGRAM_WEBHOOK_ROUTE}'
+def create_app(bot: Bot,
+               dispatcher: Dispatcher,
+               config: Config) -> Application:
+    """
+    Create aiohttp application.
+
+    :param bot: telegram bot instance.
+    :param dispatcher: telegram dispatcher instance.
+    :param config: config object.
+    :return: aiohttp Appliction.
+    """
+
+    telegram_webhook_url = f'{config.base_url}{TELEGRAM_WEBHOOK_ROUTE}'
+
+    async def on_startup(_):
+        await bot.set_webhook(telegram_webhook_url)
+
+    async def on_shutdown(_):
+        logging.warning('Shutting down')
+        await bot.delete_webhook()
+        await dispatcher.storage.close()
+        await dispatcher.storage.wait_closed()
+        session = await bot.get_session()
+        await session.close()
+        logging.warning('Bye!..')
+
+    app = Application()
+    app.add_routes(routes)
+    app.on_startup.append(on_startup)
+    app.on_shutdown.append(on_shutdown)
+    configure_app(dispatcher, app, TELEGRAM_WEBHOOK_ROUTE)
+    return app
 
 
-async def on_startup(_):
-    await telegram_bot.set_webhook(TELEGRAM_WEBHOOK_URL)
-
-
-async def on_shutdown(_):
-    logging.warning('Shutting down')
-    await telegram_bot.delete_webhook()
-    await telegram_dispatcher.storage.close()
-    await telegram_dispatcher.storage.wait_closed()
-    session = await telegram_bot.get_session()
-    await session.close()
-    logging.warning('Bye!..')
-
-
-app = web.Application()
-app.add_routes(routes)
-app.on_startup.append(on_startup)
-app.on_shutdown.append(on_shutdown)
-configure_app(telegram_dispatcher, app, TELEGRAM_WEBHOOK_ROUTE)
-
-
-__all__ = ('app',)
+__all__ = ('create_app',)