Time for iPhone v2
It is long past time for Apple to increase storage options for the iPhone and eliminate the base 16 gig model. Given how big the latest versions of iOS have become and the increased functionality of apps and user data, 16 gigs just is not enough anymore. And given that there is no option for a micro-SD card, you really need to have at least 64 gigs onboard if you have music and videos.
In fact Apple should rethink the iPhone design at this point considering the device has been out close to ten years now. User needs and the environment have changed considerably over that time. From what i hear about model 8, there will be considerable changes to the device. Even 7 will be losing the dedicated headphone jack.