diff --git a/README.md b/README.md
index cca5660fe..15975b530 100644
--- a/README.md
+++ b/README.md
@@ -69,6 +69,9 @@ export DANGEROUS_SALT='dev-notify-salt'
 export SECRET_KEY='notify-secret-key'
 export DESKPRO_API_HOST="some-host"
 export DESKPRO_API_KEY="some-key"
+export FLASK_APP=application.py
+export FLASK_DEBUG=1
+export WERKZEUG_DEBUG_PIN=off
 "> environment.sh
 ```
 
diff --git a/app.py b/app.py
deleted file mode 100644
index 2b856fa3f..000000000
--- a/app.py
+++ /dev/null
@@ -1,20 +0,0 @@
-import os
-from flask_script import Manager, Server
-from app import create_app
-
-
-application = create_app()
-manager = Manager(application)
-port = int(os.environ.get('PORT', 6012))
-manager.add_command("runserver", Server(host='0.0.0.0', port=port))
-
-
-@manager.command
-def list_routes():
-    """List URLs of all application routes."""
-    for rule in sorted(application.url_map.iter_rules(), key=lambda r: r.rule):
-        print("{:10} {}".format(", ".join(rule.methods - set(['OPTIONS', 'HEAD'])), rule.rule))
-
-
-if __name__ == '__main__':
-    manager.run()
diff --git a/app/__init__.py b/app/__init__.py
index 8cf3c7147..816ef58a7 100644
--- a/app/__init__.py
+++ b/app/__init__.py
@@ -7,7 +7,6 @@ import itertools
 import ago
 from itsdangerous import BadSignature
 from flask import (
-    Flask,
     session,
     render_template,
     make_response,
@@ -37,6 +36,7 @@ from werkzeug.exceptions import abort
 from werkzeug.local import LocalProxy
 
 from app import proxy_fix
+from app.config import configs
 from app.asset_fingerprinter import AssetFingerprinter
 from app.its_dangerous_session import ItsdangerousSessionInterface
 from app.notify_client.service_api_client import ServiceAPIClient
@@ -54,8 +54,8 @@ from app.notify_client.models import AnonymousUser
 from app.notify_client.letter_jobs_client import LetterJobsClient
 from app.notify_client.inbound_number_client import InboundNumberClient
 from app.notify_client.billing_api_client import BillingAPIClient
+from app.commands import setup_commands
 from app.utils import get_cdn_domain
-
 from app.utils import gmt_timezones
 
 login_manager = LoginManager()
@@ -82,10 +82,8 @@ billing_api_client = BillingAPIClient()
 current_service = LocalProxy(partial(_lookup_req_object, 'service'))
 
 
-def create_app():
-    from app.config import configs
-
-    application = Flask(__name__)
+def create_app(application):
+    setup_commands(application)
 
     notify_environment = os.environ['NOTIFY_ENVIRONMENT']
 
@@ -128,40 +126,12 @@ def create_app():
 
     application.session_interface = ItsdangerousSessionInterface()
 
-    application.add_template_filter(format_datetime)
-    application.add_template_filter(format_datetime_24h)
-    application.add_template_filter(format_datetime_normal)
-    application.add_template_filter(format_datetime_short)
-    application.add_template_filter(format_time)
-    application.add_template_filter(valid_phone_number)
-    application.add_template_filter(linkable_name)
-    application.add_template_filter(format_date)
-    application.add_template_filter(format_date_normal)
-    application.add_template_filter(format_date_short)
-    application.add_template_filter(format_datetime_relative)
-    application.add_template_filter(format_delta)
-    application.add_template_filter(format_notification_status)
-    application.add_template_filter(format_notification_status_as_time)
-    application.add_template_filter(format_notification_status_as_field_status)
-    application.add_template_filter(format_notification_status_as_url)
-    application.add_template_filter(formatted_list)
-    application.add_template_filter(nl2br)
-    application.add_template_filter(format_phone_number_human_readable)
-
-    application.after_request(useful_headers_after_request)
-    application.after_request(save_service_after_request)
-    application.before_request(load_service_before_request)
-
-    @application.context_processor
-    def _attach_current_service():
-        return {'current_service': current_service}
+    add_template_filters(application)
 
     register_errorhandlers(application)
 
     setup_event_handlers()
 
-    return application
-
 
 def init_csrf(application):
     csrf.init_app(application)
@@ -185,6 +155,13 @@ def init_csrf(application):
 
 
 def init_app(application):
+    application.after_request(useful_headers_after_request)
+    application.after_request(save_service_after_request)
+    application.before_request(load_service_before_request)
+
+    @application.context_processor
+    def _attach_current_service():
+        return {'current_service': current_service}
 
     @application.before_request
     def record_start_time():
@@ -519,3 +496,25 @@ def setup_event_handlers():
     from app.event_handlers import on_user_logged_in
 
     user_logged_in.connect(on_user_logged_in)
+
+
+def add_template_filters(application):
+    application.add_template_filter(format_datetime)
+    application.add_template_filter(format_datetime_24h)
+    application.add_template_filter(format_datetime_normal)
+    application.add_template_filter(format_datetime_short)
+    application.add_template_filter(format_time)
+    application.add_template_filter(valid_phone_number)
+    application.add_template_filter(linkable_name)
+    application.add_template_filter(format_date)
+    application.add_template_filter(format_date_normal)
+    application.add_template_filter(format_date_short)
+    application.add_template_filter(format_datetime_relative)
+    application.add_template_filter(format_delta)
+    application.add_template_filter(format_notification_status)
+    application.add_template_filter(format_notification_status_as_time)
+    application.add_template_filter(format_notification_status_as_field_status)
+    application.add_template_filter(format_notification_status_as_url)
+    application.add_template_filter(formatted_list)
+    application.add_template_filter(nl2br)
+    application.add_template_filter(format_phone_number_human_readable)
diff --git a/app/commands.py b/app/commands.py
new file mode 100644
index 000000000..c13dfee18
--- /dev/null
+++ b/app/commands.py
@@ -0,0 +1,11 @@
+from flask import current_app
+
+
+def list_routes():
+    """List URLs of all application routes."""
+    for rule in sorted(current_app.url_map.iter_rules(), key=lambda r: r.rule):
+        print("{:10} {}".format(", ".join(rule.methods - set(['OPTIONS', 'HEAD'])), rule.rule))
+
+
+def setup_commands(application):
+    application.cli.command('list-routes')(list_routes)
diff --git a/application.py b/application.py
new file mode 100644
index 000000000..f46d830c6
--- /dev/null
+++ b/application.py
@@ -0,0 +1,6 @@
+from flask import Flask
+from app import create_app
+
+app = Flask('app')
+
+create_app(app)
diff --git a/requirements.txt b/requirements.txt
index 27ed7fe20..398a94219 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,6 +1,5 @@
 ago==0.0.92
 Flask==0.12.2
-Flask-Script==2.0.5
 Flask-WTF==0.14.2
 Flask-Login==0.4.0
 
diff --git a/scripts/run_app.sh b/scripts/run_app.sh
index 1e3c4bf73..67eb6dd17 100755
--- a/scripts/run_app.sh
+++ b/scripts/run_app.sh
@@ -1,4 +1,4 @@
 #!/bin/bash
 
 source environment.sh
-python3 app.py runserver
+flask run -p 6012
diff --git a/tests/app/main/test_choose_time_form.py b/tests/app/main/test_choose_time_form.py
index f67af5402..77e9449f0 100644
--- a/tests/app/main/test_choose_time_form.py
+++ b/tests/app/main/test_choose_time_form.py
@@ -34,7 +34,7 @@ def test_form_contains_next_24h():
 
 
 @freeze_time("2016-01-01 11:09:00.061258")
-def test_form_defaults_to_now():
+def test_form_defaults_to_now(client):
     assert ChooseTimeForm().scheduled_for.data == ''
 
 
diff --git a/tests/conftest.py b/tests/conftest.py
index d3a2a1a7d..8f9273fc1 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -5,7 +5,7 @@ from unittest.mock import Mock
 
 import pytest
 from notifications_python_client.errors import HTTPError
-from flask import url_for
+from flask import url_for, Flask
 from bs4 import BeautifulSoup
 
 from app import create_app
@@ -31,17 +31,16 @@ from . import (
 
 @pytest.fixture(scope='session')
 def app_(request):
-    app = create_app()
+    app = Flask('app')
+    create_app(app)
 
     ctx = app.app_context()
     ctx.push()
 
-    def teardown():
-        ctx.pop()
-
-    request.addfinalizer(teardown)
     app.test_client_class = TestClient
-    return app
+    yield app
+
+    ctx.pop()
 
 
 @pytest.fixture(scope='function')
diff --git a/wsgi.py b/wsgi.py
index 35092e5f3..4fc722299 100644
--- a/wsgi.py
+++ b/wsgi.py
@@ -1,13 +1,17 @@
-from whitenoise import WhiteNoise
 import os
 
-from app import create_app  # noqa
+from flask import Flask
+from whitenoise import WhiteNoise
+
+from app import create_app
 
 PROJECT_ROOT = os.path.dirname(os.path.abspath(__file__))
 STATIC_ROOT = os.path.join(PROJECT_ROOT, 'app', 'static')
 STATIC_URL = 'static/'
 
-application = WhiteNoise(create_app(), STATIC_ROOT, STATIC_URL)
+app = Flask(__name__)
+create_app(app)
+application = WhiteNoise(app, STATIC_ROOT, STATIC_URL)
 
 if __name__ == "__main__":
     application.run()