PokeSniper have stopped working but PokeDexs ( https://pokedexs.com/ ) is currently the best alternative as it allows you to quickly snipe Pokemon using the Poke Sniper function, which is perfect and pretty straightforward for anyone using the PokeSniper2 app on Android.
Thanks for sharing this.
PokeDexs is a really great sniper alternative site but I have seen that mostly it is very hard to find coordinates for rare and strong Pokemon with high IVs, which is important to complete your PokeDex and win battles in the gym.
To help our fellow Pokemon players and trainers, I have found a couple of sniping sites, both of them are pretty new and provides some additional information about the Pokemon you are going to catch. And the best thing is, they are compatible with Pokemon GO Gen 2: