diff --git a/README.md b/README.md
--- a/README.md
+++ b/README.md
@@ -7,12 +7,20 @@
 
 Boot applications by using plugins.
 
+### Motivation
+
+Simplify to create an application in Haskell.
+
+When we decide to create an application using Haskell. We may need using configurations, loggers as basic functions. If this application needs storages, caches, etc., then we have to weaving the management of connection of these facilities into the application. Connections need to be created before and be destroyed after using them. There is a common strategy to manage connections, that is using `Control.Monad.Cont`. Then we can encapsulate the management of connections separately. For example, we can write a database plugin `Plugin cxt m DBConnection`, which can manage the database connections in monad `m` with context `cxt`. Context `cxt` may be requested for configurations or logging functions. When all the components of application are encapsulated by plugins, then building an application will be simplified.
+
+### Have a Try
+
 ```Haskell
 main :: IO ()
-main = booting (pluginSimple "application") go
+main = bootApp (pluginSimple "application") go
   where
     go = forever $ do
-      user <- require "user"
-      logInfo $ "Hello, " <> user <> "!"
+      user <- require "user"              -- Request for configuration.
+      logInfo $ "Hello, " <> user <> "!"  -- Request for logging.
       liftIO $ threadDelay 1000000
 ```
diff --git a/boots.cabal b/boots.cabal
--- a/boots.cabal
+++ b/boots.cabal
@@ -1,6 +1,6 @@
 cabal-version: 1.12
 name: boots
-version: 0.0.1
+version: 0.0.2
 license: MIT
 license-file: LICENSE
 copyright: 2019 Daniel YU
@@ -30,7 +30,7 @@
     default-language: Haskell2010
     default-extensions: FlexibleInstances MultiParamTypeClasses
                         GeneralizedNewtypeDeriving OverloadedStrings RecordWildCards
-                        FlexibleContexts
+                        FlexibleContexts RankNTypes ScopedTypeVariables
     build-depends:
         base >=4.10 && <5,
         data-default >=0.7.1.1 && <0.8,
@@ -52,7 +52,7 @@
     default-language: Haskell2010
     default-extensions: FlexibleInstances MultiParamTypeClasses
                         GeneralizedNewtypeDeriving OverloadedStrings RecordWildCards
-                        FlexibleContexts
+                        FlexibleContexts RankNTypes ScopedTypeVariables
     build-depends:
         base >=4.10 && <5,
         boots -any,
@@ -84,7 +84,7 @@
     default-language: Haskell2010
     default-extensions: FlexibleInstances MultiParamTypeClasses
                         GeneralizedNewtypeDeriving OverloadedStrings RecordWildCards
-                        FlexibleContexts
+                        FlexibleContexts RankNTypes ScopedTypeVariables
     build-depends:
         base >=4.10 && <5,
         data-default >=0.7.1.1 && <0.8,
diff --git a/main/Main.hs b/main/Main.hs
--- a/main/Main.hs
+++ b/main/Main.hs
@@ -5,7 +5,7 @@
 import           Control.Monad
 
 main :: IO ()
-main = booting (pluginSimple "application") go
+main = bootApp (pluginSimple "application") go
   where
     go = forever $ do
       logInfo "Hello, world!"
diff --git a/src/Boots.hs b/src/Boots.hs
--- a/src/Boots.hs
+++ b/src/Boots.hs
@@ -8,11 +8,40 @@
 --
 -- Boot application by using plugins.
 --
+-- * Motivation
+--
+-- Simplify to create an application in Haskell.
+--
+-- When we decide to create an application using Haskell.
+-- We may need using configurations, loggers as basic functions. 
+-- If this application needs storages, caches, etc., 
+-- then we have to weaving the management of connection of these facilities into the application. 
+-- Connections need to be created before and be destroyed after using them. 
+-- There is a common strategy to manage connections, that is using `Control.Monad.Cont`. 
+-- Then we can encapsulate the management of connections separately. 
+-- For example, we can write a database plugin `Plugin` @cxt@ @m@ @DBConnection@, 
+-- which can manage the database connections in monad @m@ with context @cxt@. 
+-- Context @cxt@ may be requested for getting configurations or logging functions. 
+-- When all the components of application are encapsulated by plugins, then building an application will be simplified.
+--
+-- * Have a Try
+--
 -- >>> booting (pluginSimple "application") (logInfo "hello")
 -- 2019-07-27 19:35:30  INFO [application] Ghci1 - hello
 -- >>> booting (pluginSimple "application") (require "user" >>= logInfo)
 -- 2019-07-27 19:37:45  INFO [application] Ghci2 - daniel
 --
+-- Main
+-- 
+-- > main :: IO ()
+-- > main = bootApp (pluginSimple "application") go
+-- >   where
+-- >     go = forever $ do
+-- >       user <- require "user"              -- Request for configuration.
+-- >       logInfo $ "Hello, " <> user <> "!"  -- Request for logging.
+-- >       liftIO $ threadDelay 1000000
+--
+
 module Boots(
     module Boots.Internal
   , module Boots.Plugin
diff --git a/src/Boots/Internal.hs b/src/Boots/Internal.hs
--- a/src/Boots/Internal.hs
+++ b/src/Boots/Internal.hs
@@ -9,17 +9,22 @@
 -- Boot cores.
 --
 module Boots.Internal(
-  -- * Main function
-    booting
+  -- * Plugin
+    boot
+  , module Boots.Internal.Plugin
   -- * Application
+  , bootApp
   , module Boots.Internal.App
-  -- * Application plugin
-  , module Boots.Internal.Plugin
   ) where
 
 import           Boots.Internal.App
 import           Boots.Internal.Plugin
 
--- | Run application using a plugin. Context @cxt@ can't escape from @m@.
-booting :: Plugin () m cxt -> AppT cxt m () -> m ()
-booting plugin app = runPlugin () plugin (`runAppT` app)
+-- | Run application only in plugin.
+boot :: Monad m => Plugin () m (m ()) -> m ()
+boot plugin = runPlugin () plugin id
+
+-- | Run application in context with the help of plugin. Context @cxt@ can't escape from @m@.
+--  If you want to define your own `AppT` then please use 'boot' or 'runPlugin'.
+bootApp :: Plugin () m cxt -> AppT cxt m () -> m ()
+bootApp plugin app = runPlugin () plugin (`runAppT` app)
diff --git a/src/Boots/Internal/App.hs b/src/Boots/Internal/App.hs
--- a/src/Boots/Internal/App.hs
+++ b/src/Boots/Internal/App.hs
@@ -10,6 +10,7 @@
 --
 module Boots.Internal.App(
     AppT
+  , App
   , runAppT
   , liftIO
   , ask
@@ -17,7 +18,6 @@
   , throwM
   ) where
 
-import           Boots.Internal.Plugin
 import           Control.Monad.Catch
 import           Control.Monad.IO.Unlift
 import           Control.Monad.Reader
@@ -25,6 +25,9 @@
 -- | Application monad transformation.
 newtype AppT cxt m a = AppT { unAppT :: ReaderT cxt m a }
   deriving (Functor, Applicative, Monad, MonadTrans, MonadReader cxt, MonadIO, MonadThrow, MonadCatch, MonadMask)
+
+-- | Simple IO monad.
+type App cxt = AppT cxt IO
 
 -- | Run application monad transformation.
 runAppT :: cxt -> AppT cxt m a -> m a
diff --git a/src/Boots/Internal/Plugin.hs b/src/Boots/Internal/Plugin.hs
--- a/src/Boots/Internal/Plugin.hs
+++ b/src/Boots/Internal/Plugin.hs
@@ -1,5 +1,3 @@
-{-# LANGUAGE GeneralizedNewtypeDeriving #-}
-{-# LANGUAGE MultiParamTypeClasses      #-}
 -- |
 -- Module:      Boots.Internal.Plugin
 -- Copyright:   2019 Daniel YU
@@ -16,6 +14,7 @@
   , promote
   , withPlugin
   , mapPlugin
+  , isoPlugin
   , bracketP
   ) where
 
@@ -50,11 +49,16 @@
 withPlugin :: (i -> j) -> Plugin j m u -> Plugin i m u
 withPlugin f = Plugin . withReaderT f . unPlugin
 
+-- | Transform a plugin with monad @n@ to a plugin with monad @m@.
+isoPlugin :: (m () -> n ()) -> (n () -> m ()) -> Plugin i n u -> Plugin i m u
+isoPlugin f g = Plugin . mapReaderT go . unPlugin
+  where
+    go (ContT fnc) = ContT $ \mc -> g $ fnc (f . mc)
+
 -- | Apply a function to transform the result of a continuation-passing computation.
 mapPlugin :: (m () -> m ()) -> Plugin i m u -> Plugin i m u
 mapPlugin f = Plugin . mapReaderT (mapContT f) . unPlugin
 
-
 -- | Create bracket style plugin, used for manage resources, which need to open and close.
 --
 -- A simple example:
@@ -65,7 +69,7 @@
 -- using
 -- close
 bracketP
-  :: MonadCatch m
+  :: forall m i u. MonadCatch m
   => m u          -- ^ Open resource.
   -> (u -> m ())  -- ^ Close resource.
   -> Plugin i m u -- ^ Resource plugin.
@@ -73,8 +77,8 @@
   where
     {-# INLINE go #-}
     go f u = do
-      v <- try (f u)
-      cl u
+      v <- try $ f u
+      _ <- try $ cl u :: m (Either SomeException ())
       case v of
         Left  e -> throwM (e :: SomeException)
         Right x -> return x
diff --git a/src/Boots/Plugin/Logger.hs b/src/Boots/Plugin/Logger.hs
--- a/src/Boots/Plugin/Logger.hs
+++ b/src/Boots/Plugin/Logger.hs
@@ -22,13 +22,13 @@
   , logOther
   ) where
 
-import Data.Monoid((<>))
 import           Boots.Internal
 import           Boots.Plugin.Salak
 import           Control.Monad
 import           Control.Monad.Logger.CallStack
 import           Control.Monad.Reader
 import           Data.Default
+import           Data.Monoid                    ((<>))
 import           Data.Text                      (Text, toLower, unpack)
 import           Data.Word
 import           Lens.Micro
diff --git a/test/Spec.hs b/test/Spec.hs
--- a/test/Spec.hs
+++ b/test/Spec.hs