FEATURES : Calculation : - Two Calculation method: functional or sequential - Three rounding mode: rounding , up or cut - Number of digits after the decimal point: free , zero , one , two , three or four - Angle unit: degree or radian Appearance : - Color or Wallpaper: Set the wallpaper with a photograph or a camera, or select a background color - Number Format: Select a digit grouping and decimal point from among the 8 types including India format - Sound of buttons : Select the button sound from nine timbres or turn off Result: - Character color: Freely set color by the slider - Background color: Freely set color and opacity by the slider - Expression color: Freely set color or hide by the slider Button : - Shape: Square , Round Square , Circle , Diamond , Heart or Cogwheel - Size: Large , Medium or Small - Dimensions: Flat , Solid or Outline - Character color: Freely set color by the slider - Background color: Freely set color and opacity by the slider - Position: The position of buttons are freely changed - Function button : Three function buttons can be changed, thease button is include Grand total, Rand, Sine,1/x, Route, etc... History : - Equals: Over write last result or Add the result the history - Vertical (portrait) mode: Indication Left , Hidden or Indication Right - Horizontal (landscape) mode: Indication place Left or Right - character color: Freely set color by the slider - background color: Freely set color and opacity by the slider - Expression color: Freely set color or hide by the slider SUPPORTS : Non retina and Retina display on iPhone, iPad and iPod Touch. iPhone 4 to 8 Plus, iPhone SE and iPhone X, iPad 2 to iPad Pro and iPad mini to iPad mini 4 , iPod touch 3gen and later. iOS 8.0 and later. There is also a paid version without ads.