If you see a Pokémon near you on the map, it is there on the game servers, so you are guaranteed to find it if you go to the location on the map. This lets you skip the entire radar function, and makes it a lot easier to catch lots of Pokémon fast.
|Here is what the website looks like.|
The only downsite with the PokéVision website is that it will not display all Pokémons available, because those affected by lure/incense is only visible to you, so they cannot be added on the map.
The website currently has an issue because it has a lot of visitors, so you might need to refresh it a few times in order to get it to work. Happy hunting!