I have an app on my android phone called the "ISS Detector". It's free and it's amazing. You can set up an alarm for when the ISS is due overhed. When you access the app, it tells you when it will appear, predicted weather conditions, and a screen comes up that points you where to look on two axes. It's accurate to within a second or so.
I also added the Iridium Detector to it. The Iridium satellites constellation consists of 66 satellites for communication. They appear as a flash of light momentrily. It's just amazing the technology that tells you when and where to look for a flash of sunlight bouncing off a satellite and it works! People are just floored when I point into the night sky at a point in space and tell them to look for a flash or streak of light and it appears.
Tonight, ISS at 20:35:48 to 20:41:14 and 3 Iridium flashes.