The iPhone 6S and 6S+ released in September of 2015, following the iPhone 6 and 6+ in 2014. It came in 4 colors, Silver, Space Gray, Gold, and a new one, Rose Gold, a slightly pinkish gold finish. Below is my full review and personal thoughts on it.
Tech Specs: Sizes: 6S, 6S+ Colors: Silver, Space Gray, Gold, Rose Gold Storage: 32GB, 64GB (not available in store or online), 128GB Screen Size: 4.7 in (6S), 5.5 in (6S+) Display: Retina LCD HD Display Rear Camera: 12MP, Live Photo, f2.2 Aperture, HDR, True Tone Flash, 4K Video Selfie Camera: 5MP Retina Flash, 720p Recording, Unlock: Touch ID, Customizable Password
Display: The display is a Retina HD, LCD (Liquid Crystal) display. Although it isn't a fancy OLED or True Tone display, it is a very good and bright display. It display a lot of colors, and is also the perfect size. It has something called 3D Touch, which is a technology which detects the hardness of the press of you finger, and displays different actions. If that doesn't make sense, it just means you can hard press on apps or different buttons on-screen to access different options. Like if you 3D Touch on "Settings", if will show you options to go into the Battery tab, the Wi-Fi tab, the Cellular tab, and the Bluetooth tab, instead of clicking on the app and searching for the tabs manually. It is also very hard to crack, as I personally have dropped it on concrete many times, and hasn't cracked.
Cameras: The rear camera is 12MP (megapixel) Camera with a f2.2 aperture, and 4K Video. It also has something called Live Photo, which is when you take a photo, it captures a few seconds before and after the photo is taken. This can be turned on and off, and it takes up only a little bit more storage, but not a lot. The rear camera is very great, and takes very good photos in the day, but when it comes to nighttime photos, a better phone is the iPhone 7 and 7+. The front facing camera is also very good. It is 5MP, and has 720p filming, or for FaceTime. It also has Live Photo, but I recommend using the front facing camera in Snapchat, as the local camera app flips front facing photos and videos, where as Snapchat does not. Overall, the camera is great.
Audio: The iPhone 6S and 6S+ both have a 5 dot audio grill, and 2 microphones. The quietest setting of sound is very quiet, which can be good and bad, but the loudest audio setting is very loud. It projects audio that can be heard from around 30 feet away, which in book is very loud. It has a good bass that can be felt slightly on the screen, and has around a 75 decibel rating. Overall, the audio is loud, but for a louder experience, I would go with the iPhone 7, 7+, 8, 8+, or X.
Battery: The battery is good, with personally a 5 hour battery life. I charge the battery every single night, because I like to have 100% when I wake up, but Apple does not recommend that. I just do it because I own a battery case so it doesn't really matter. It comes with around 10 hours of Internet use on Wi-Fi, but it wears down over time. You can get a battery replacement for $29, up until December 2018.
Overall, the iPhone 6S and 6S+ are really great phones, because they have a real home button and a headphone jack, but also because they are a good price and great quality phones.