You are very unlikely to have your Pokemon GO account banned for using PokeNotify. Here's why:
- PokeNotify does not talk to Niantic's servers from your phone. PokeNotify talks to a "middle-man" service. This middle-man service uses its own Pokemon GO accounts, not the user's personal Pokemon GO account, set up on his/her phone. So the accounts used are in no way tied to user Pokemon GO accounts. In addition, since a middle-man service is being used, things like your phone's unique footprint (IP address, Android version, phone model, etc) that could be used to identify you are never passed to Niantic's servers through PokeNotify.
- Because of how much "noise" there is in this location data. Location services on your phone can vary in their accuracy of finding your exact location over time, as you go under bridges, into buildings, move to areas with less reception, etc. The middle-man service queries using your location once per minute at all times during the day, while Pokemon GO queries Niantic's servers for Pokemon using your location every 10 seconds or so, but only when the Pokemon GO app is actually open. So the times and exact latitude/longitude of location data received by Niantic's servers are unlikely to match up between queries sent by the Pokemon GO app, and queries sent by the middle-man service.
- In addition, you are protected by the "noise of the crowd," in two ways:
- 1: You are not the only one in your area sending location data to Niantic's servers, everyone around you playing Pokemon GO is also sending that location data. So if you're at a PokeStop with a lure, or just walking around the city, or even just hanging out in your backyard with a friend, in all cases there are multiple people in the same location all playing Pokemon GO and sending their location data to Niantic. Because of this, Niantic has no way to distinguish which users in a location are using PokeNotify, and which are not. Niantic is not going to risk banning users it is not sure are using PokeNotify -- remember they are trying to get as many users playing this game as possible, and trying to make money off of each and every user.
- 2: You're not the only person in your area using PokeNotify. Over 100,000 people have already downloaded PokeNotify, and that's just in its first few days available. All of these people are looking for Pokemon in their area. The middle-man service is smart though -- it doesn't look for Pokemon in an area if its already looked in the last couple minutes. Instead, it just continues to use that slightly-stale data when responding to the PokeNotify app. So every couple minutes, only one user using PokeNotify in your area is actually having their location sent, and that user is very unlikely to be you, more and more as more users use PokeNotify. And due to users turning off their phones, enabling / disabling the PokeNotify app at different times, and changing locations, this means there's probably a different user's location used for your area every couple minutes, not the same user's location every time. So its actually in every PokeNotify user's best interest to get other Pokemon GO players to use the app. Tell your friends to download the app here.
On top of all of the above, future versions of PokeNotify will have a feature so that not even the middle-man service knows your exact latitude / longitude location. Instead, the PokeNotify app will modify your exact latitude / longitude to randomly place you between 10 and 150 meters from your true location, and send that location data to the middle-man service. So even if your "location" is sent to the middle-man service, and even if you're the only player using PokeNotify / Pokemon GO in your area, Niantic still won't be able to find a connection to your Pokemon GO account through location data. UPDATE 8/10/16 - This feature is now implemented.
Don't know if you should trust my analysis? This article was posted to Reddit for peer review so others could comment on whether this analysis has any holes or not. You can read others' feedback, or post your own feedback, here.
Here's one very good point from the peer review to add to the analysis above:
"It's incredibly unlikely Niantic is even tracking these third-party products at this time, and even less likely they will ban anyone for using them.
Even in the longer term, it's much, much more likely they'll shut down the apps than start randomly banning people for using them. Even if they do ban people, shutting down the apps will come first, as will copious warnings, as will a drastic overhaul of the tracking system, unless they feel like flushing money and goodwill down the toilet like a drug-addict during a SWAT raid."