Free42 vs Solve - A colorful calculator

Free42 is an open-source programmable calculator app designed to emulate the HP-42S calculator. It provides RPN mode, programming capability, expandability via packages, and accurate emulation of the original HP-42S.

Solve is a free calculator app for Android and iOS that has a colorful and intuitive interface. It includes a basic calculator as well as converters, date calculators, and other specialty tools. The app is designed to be easy to use while also offering advanced math and conversion features.