def init_manager(app, db, **kwargs):
    """
    Initialise Manager

    :param app: Flask app object
    :parm db: db instance
    :param kwargs: Additional keyword arguments to be made available as shell context
    """
    manager.app = app
    manager.db = db
    manager.context = kwargs
    manager.add_command('db', MigrateCommand)
    manager.add_command('clean', Clean())
    manager.add_command('showurls', ShowUrls())
    manager.add_command('shell', Shell(make_context=shell_context))
    manager.add_command('plainshell', Shell(make_context=shell_context,
        use_ipython=False, use_bpython=False))
    return manager