Superphones are smartphones with high-end features to make them more capable than basic smartphones. The term was introduced when Google launched the Nexus One.
It implies high-end functionality beyond the basic criteria for a smartphone, such as the ability to be more tailored to a users needs than just being able to extend a selected set of software ("mobile apps"). A Superphone also implies newer technology, and newer software. For example, having the newest SoC chip made from OEM's such as Qualcomm or Intel.
An example of a Superphone is the LG G Flex 2. The phone sports a body that is curved horizontally, this makes the phone much less likely to break when bent or in a scenario where one sits on the phone by accident. The back of the G Flex 2 is coated with a material that 'self-heals' within minutes when scratched.
Many flagship smartphones from various OEM's (Samsung, LG, HTC) are considered to be Superphones, as the term flagship refers to the OEM's most high-end offering.
Plausible criteria for Superphones in 2016 include: