There is a new app for iOS/browsers (soon for Android) called www.pokemonradargo.com. Users can add locations for specific Pokemon they saw or caught. But I doubt the usefulness of such an app. Will a specific Pokemon actually repeat their spawn location in Pokemon Go?
This post about spawns does not answer this: How do I find Pokémon?
This one: How long until a pokemon respawns in the same spot?, is about different Pokemon spawning in the same spot, not the same Pokemon each time.
In addition to Thebluefish's answer I will add some details.
OVERALL, IT'S RANDOM
The randomness of pokemon spawning around your area, are essential to give everyone a unique gaming experience. But there are some factors we could rely to expect a greater chance to catch a pokemon within an area.
1. Rarity Let's give the fact that there are the most common pokemons like Rattata, Zubats, etc...
The rarity of these spawns, MIGHT BE proportion to the egg kilometer category they belong. Thus you can expect the quanity of spawns upon this, but of course it does not gauratee to be of same type.
2. Nests already mentioned by Thebluefish, nests will ensure that a particular pokemon will spawn overtime in that particular range of area, proven by experience, also introduced by pokemon go community, and here are some topics about pokemon nest for you to get started Pokemon Go Nest Find Silph Road Nest Articles
Notes:
1. Once Niantic have allowed live locating of pokemons, that enable developers to build apps like the famous Pokevision, which allows you to see live, where does natural spawn pokemons do spawn and when they will despawn. Be also aware that there are 2 types of pokemon spawn, natural and lure.
2. I don't have any reference but there are assuptions that certain type of pokemons will spawn based on area content, for example neardby water areas have greater possibility to spawn water type pokemons. Based on my experience, I don't find it to be always true, but I did once caught 3 Lapras within one day on a nearby water area.
I dont know how much help this is but its the best i have so far: Over a 24 hour period a dragonite spawned in the same area of a park 3 times, twice within 15 minutes. I dont know if it was a fluke and i will never see one there again or if it will be back, but if one showed up 3 times within an area of about 500 meters i would have to guess that they spawn in the same kind of area each time. If it shows up there again i will do my best to remember to update this post.
A friend also reported that a ryhorn spawns in a park near them frequently. Again, i dont know yet, i was looking for an answer to the same queation (didnt catch any of the 3 dragonites and wanted to know if/when i would have another chance) but looking at the information i have it seems like the spawns are the same and it just randomises what time they show up.
Based on information I've read from the Silph Road (cannot find source, will edit if I do), there are nests where a specific type of Pokemon will spawn. O have found multiple of these nests nearby, one with 3-6 Charmane at any time, and another with 2-4 Jynx at a time.
I located these via Pokevision with great success. These spots have consistently spawned their respective Pokemon over several days of monitoring.
I caught 2 pikachus at my place of employment on different nights. I don't see them very often. I have seen 3 and 2 of them were at night at my place of employment. I don't know if this is an indicator that they will continue to spawn here or if it was just a freak thing. But, I am also curious to know if the Pokemon spawn in the same locations time after time.
There's a park near my doctors office.
Every week I have an appointment at 2pm on Wednesdays.
Since the game went live I always see a snorlax there on my way home.
Also, the gym that is there has a snorlax at it.
For this reason I believe that it is very likely that pokemon will spawn at the same place in some sort of pattern.
Which Pokemon spawn is based on characteristics of the location (terrain, climate, etc.), so if the characteristics are right for it to spawn once, chances are it will eventually spawn again. Knowing that more than one has spawned would definitely be a stronger indicator, but even with just one, at least you know it's happened once. Consider the app as a suggestion on places to look for Pokemon you've never seen rather than an absolute guarantee that you'll find one at that location.
