Spin Con is an easy-to-use unit converter, capable of converting between several units within different size classes.
Interface:
--Single-view display with a single text input for unit values
--Output box displays the result of the conversion
--Two unit boxes display the currently selected units
--Units are selected via a dual-picker, and the results update automatically with each swipe or tap of the wheels
--Lower multi-component button opens different unit categories: "Size", which contains the length, area, and volume classes, and "Other", which contains the time, mass, and energy classes
--Upper multi-component button displays the unit classes of the currently selected category and update the pickers automatically when selected
Features:
--336 total units included, classified by distance, area, and volume, time, mass, and energy (56 units each)
--18,816 possible conversions total across all unit classes
--units range from nanoscopic to galactic and everything in between
--pickers spin back to the SI unit of measurement (meters, seconds, kilograms, joules, etc.) by default whenever the type is changed for easier navigation
In addition to the support and developer pages, there is also a page on facebook.
Search for "Jesse Winchesters iPhone Apps", and keep up to date on new additions.