Playing Pokemo Go with the help of Ingress App.
Prior to the development of Pokemon Go, the company that made Pokemon Go developed a similar location based augmented reality game named Ingress.
The Pokemon Gym and Poke-Stops location are based on data gathered by players playing Ingress in the past.
Therefore it is possible to use Ingress to find key locations in Pokemon Go.
Using Ingress App to Gather Information
Download the Ingress App.
Android - https://play.google.com/store/apps/details?id=com.nianticproject.ingress&referrer=utm_source%3Dingress%26utm_medium%3Dwebsite%26utm_campaign%3Ddownload
iOS - https://itunes.apple.com/us/app/ingress/id576505181?mt=8&ign-mpt=uo%3D4
Launch the app and follow the instructions to setup your account. After setting up the account the app will detect your location and send you to a map view of the Ingress universe.
From the Ingress app, you can see glowing dots that they call the XM. The glowing dots are very likely pokemon spawn locations in Pokemon Go.
For Pokemon Gyms and PokeStops, they are the portal equivalent in Ingress. Ingress provided a useful tool for players to discover portal locations around the world without traveling to them.
You can use it here at https://www.ingress.com/intel. Search for the location in top right hand location and you will be able to see all the portals in the surrounding area.