Basically, you have two options to get the results:
- Scrape
- Use the Google Places API.
The Google Places API is very expensive. It starts at ~0.03$ per request, which means that the tool would have to pay 3.63$ for a 11x11 grid. And this is for one keyword and one scan. If you add some profit for the tool provider, you can understand why nobody is using the API.
The other option is to scrape Google Maps results. Here, you have many variables that can differ between providers. For example, to fake the location, you need to calculate the altitude, for which you need the Earth's radius. Different providers may use different numbers for the Earth's radius (+-10 km), which can produce different results.
There are different formulas to calculate latitude and longitude, different ways to fake location, and different zoom levels to use. Some are using circles, some are avoiding water and so on. Every small difference can produce different results.
The main point is that the
Earth is not flat, and consistency is the important part.