IPv4 Address Calculator app for iPhone and iPad

Simple and intuitive IPv4 address calculator (henceforth referred to as IP address for short). Given an IP address, and (optionally) a slash number / network mask, provides the network address, broadcast address, and the range of usable IP addresses (from the first to the last). Adopts the popular conventions that there are no host addresses in a /31 network (just a network address and a broadcast address, making it a degenerate network that is not very useful), and /32 refers to a single IP address.

Features include:
(a) No typing needed to specify IP addresses, subnet masks, etc. (conveniently use input methods like scroll wheel and slider)
(b) Illustrates how each IP address can be interpreted as a classful or as a classless address (showing calculations for both cases).
(c) Illustrates how the "slash notation" corresponds to the a unique network mask and a unique wildcard mask, and a specific number of usable host addresses.

Useful for:
(a) routine IP address calculations for IT professionals like network administrators and system administrators
(b) IT professionals preparing for IT certification exams like CCNA, Huawei, Comptia Network+, etc.
(c) students in computer science and/or engineering interested in computer networking and IP networking

This regular version (not the lite version) is ad-free, and has additional features, such as the ability to enable detection of special addresses (reserved, private, APIPA, loopback, and even shared address space addresses -- see the April 2012 RFC 6598, for instance -- to the best of our knowledge, ours is the only app that recognizes RFC 6598 / shared address space addresses), which can be turned on or off in the Settings app.