That app is too primitive. We made this because we felt the need for this.
Location reminder is a very nice idea. I would like to use it, for myself only (but it would be much better if I could make my friends use it), but I can't. Using smartphones with lots of apps destroys my life (and my battery).
We are trying our best to keep the battery usage minimum. We are currently using the GCM service for all our push notifications. It helps in keeping battery usage low since the same service handles all the Android notifications.
It is a shame that everything are apps and for them to work we need to convince people to install them and keep them running.