ISS Info can tell you when you can next see the International Space Station over a location of your choice. You can also ask where it is right now, who is on board, what's the latest news about the ISS, or just ask for a fact about the whole mission.
If the city is in your own country, then you just need to say the city name, but if you want to know about passes in other countries, then don't forget to add the country name in your request.
You can also ask for sightings from where you are right now if you have a location associated with your device. Just ask ISS Info "When can I see it from here" and grant permission for ISS Info to see your location (we only need approximate latitude and longitude, not your street address, and we don't keep any data after the prediction)