just added some existing Flask tool

Author: Dorianux

doc/tools.rst

@@ -100,6 +100,9 @@ various Python frameworks and libraries.
  :mod:`repoze.what`.
 * `mongobox <http://github.com/theorm/mongobox>`_ is a tool to run a sandboxed
  MongoDB instance from within a python app.
+* `Flask-MongoAlchemy <http://github.com/cobrateam/flask-mongoalchemy/>` Add Flask support for MongoDB using MongoAlchemy.
+* `Flask-MongoKit <http://github.com/jarus/flask-mongokit/>` Flask extension to better integrate MongoKit into Flask
+* `Flask-PyMongo <http://github.com/dcrosta/flask-pymongo/>` Flask-PyMongo bridges Flask and PyMongo.
 
 Alternative Drivers
 -------------------