I know longer have any apps on GAE myself and don't intend to maintain this library. If anyone is interested in picking this up want me to point to an alternative here, please let me know.
This Flask extension provides easy integration of the excellent gae_mini_profiler.
Usage:
from flask import Flask
from flaskext.gae_mini_profiler import GAEMiniProfiler
app = Flask(__name__)
GAEMiniProfiler(app)