Let's say I'm playing a game, reading a book, surfing the net or watching a video and I'm getting close to my stop. Is there some way (perhaps an app) that can alert me that it's time to get off?

**Other situations where this app would be useful**

* Dark platforms at night where it's difficult to see where I'm at
* Crowded services where I just can't see out the window reliably
* Travel in a foreign country where signage is in a different script
* Travelling along unfamiliar routes
* Useful for other modes of public transport as well

**How it would work**

I imagine an app like this would allow the user to configure the location of the stop via maps and set the amount of lead time (e.g. I want to be alerted five minutes before we arrive). The app would then monitor progress along the route and also estimate the lead time based on progress so far or some other smart means.

Any ideas?