On release day, the app itself was great. It had a warmer/colder system with 0-3 paw prints to track down the Pokémons in your vicinity. Hunting down things you missed was a game in itself. When the servers weren't dying, the game was quite responsive too.
Fast forward a week, and the warmer/colder system is broken. All the Pokémons are always 3 steps away, which means somewhere within 1km radius. And you have 15 minutes to find that one you're missing. You can still see them from 100 meters away, and the app is quite responsive when you get close to them. The downtime is unbearable at times, and people are losing items they paid real money for due to this.
Then we fast forward two weeks. People have started reverse-engineering the internal API and are using it to create maps over nearby Pokémons. The brokenness of the tracking system is acknowledged at some convention (not publicly on their site), but no promises are made on fixing it. Niantic starts sending out C&Ds to projects using their APIs, trying to remove bots and tracking websites. Despite their own tracker being broken. The app is now limited to communicating once per 10 seconds, and you can only see Pokémons 70m around you.
After successfully hiring a PR manager, Niantic breaks their deafening silence and tells us that the tracking system will not be fixed. They will replace it with something better. A new app rolls out, now with request signing to combat tracking websites. This takes about 5 days to crack before business returns to usual. People really want to be able to track their Pokémons, and having no ways to do so put a lot of people off. Closing Pokevision made many of my friends quit, because to them, Niantic didn't share their concerns at all.
Finally, the tracking system is replaced with a new one. You can now detect nearby Pokémons up to 200m (vs 1000m before). You still need to get within 70m of them to actually see them though. Niantic also activate an extra tracking system in certain American states, as a beta test. This has been active for about two weeks now without hitting the rest of the player base. Unfortunately, it is based on Pokestops, which are user-submitted landmarks from their previous game, Ingress. A lot of places do not have these at all, or extremely few. This makes the game basically unplayable in rural areas, where you'll rapidly run out of items or never find anything interesting.
For me, personally, I feel this game has great potential, but I really miss more openness from Niantic. What are their plans for the future? Which concerns are they acknowledging? Which are intentional features of the game, and thus ignored? I think this game basically blew up in their faces, and they weren't ready to handle the interest. It's sad that they let this chance go, because I think it will be extremely hard for them to redeem themselves after this.