I was able to test the app out before public release. Despite being limited to only gen 1 Pokemon, it is fun to do something while I do my walks to stores since I do not have a car right now.
Gym battles however is very laggy for me due to my phone's performance (BLU Studio 5.0 C HD). Due to this, I am avoiding gyms until I get a new phone with a better GPU to actually do something other than catching 'mons. Also, this app EATS your battery. If you want to play in long bursts, I suggest getting a external battery.
My biggest con about this app is the lack of communication between other trainers that can be in the area. This app can go the distance if people can communicate with each other to trade/battle. Another issue is the lack of character customization. Clothing can use more variation in color and have different types of clothing, and I can not have a buzz-cut hairstyle (personal preference). Leveling up does give you some free items, but you will later depend on micro-transactions in order to continue playing.
On the upside, I can listen to Sirius XM radio while I catch all the 'mons. :3