Big Button Calculator Pro Lite, developed by Cider Software LLC, is a full version calculator app available for iPhone. It is the best calculator for iOS with its unique features that make it stand out from other calculators. One of its key features is the dual-line display, which shows both the input and result at the same time. The app also includes a percentage and backspace button, multi-line input for long equations, and automatic scientific formatting.

Big Button Calculator Pro Lite has 18 color themes to choose from, making it customizable to fit your preference. The app also includes voiceover accessibility and split view. The app's gestures make it easy to use, with the ability to swipe left on the display to backspace, swipe right to clear, and tap and hold on the result to copy or on the input to move the cursor, copy, and paste.

Overall, Big Button Calculator Pro Lite is a great app for those looking for a calculator with big buttons and colorful backgrounds. Its unique features and customizable options make it an excellent choice for anyone needing a calculator on their iPhone.