A colorful calculator with BIG buttons, LOTS of features, and fully customizable. This version is ad-supported.

・Dual-line display - shows the input and result at the same time
・History tape - saves every calculation, time and date stamped
・Memory buttons - shows its value on the display
・Percentage and backspace button
・Scientific functions
・6 layouts (3 portrait, 3 landscape)
・10 color themes
・Multi-line input for really long equations
・Automatic scientific formatting
・Label any calculation in the history tape
・E-mail a calculation or the entire history tape
・VoiceOver accessibility
・iOS 9 Split View
・3D Touch

Gestures

・Swipe down to see the history tape
・Tap & hold on the result to copy
・Tap & hold on the input to move the cursor, copy, paste, convert to E-notation

Customize

・Font Size
・Bold Font
・Color Theme
・Light Tape Background
・Show Layout Button
・Allowable Layouts
・Show Memory Buttons
・Backspace Button (Solid, Arrow)
・Replace ÷ Button With /
・Replace E Button With Hidden, EE, 00, or 000
・Show Thousands Separators
・Minimum Decimal Digits
・Maximum Decimal Digits
・Sound
・Equals Repeat
・Left-Handed Mode

URL Scheme: calculatorhdprofree://