•	Fixed an issue affecting Premium upgrades for some users
	•	Improved purchase reliability and restore behavior
	•	Added clearer navigation with back button support
	•	General improvements and bug fixes

Additional tools have been added:
   -arc length calculator
   -trigonometry calculator
   -mitered duct calculator (owl)
   -fractional output
   -round and rectangular equivalents with friction loss

Updated for IOS 11.

Added demonstration video  at support website.  Click support link for more information.