Blockpad

Blockpad is a new-age spreadsheet application designed specifically for engineers. Its main goal is to combine the best of both advanced math calculation apps and renowned spreadsheet apps such as Excel.
Boasting a unique math and formula engine developed in-house, Blockpad has the following advantages: easy formula input, support for math-style equations, word processing, spreadsheets, CAD sketching, link sketches to calculations, equation solving, calculus functions, engineering reference data, and the ability to automatically recalculate (just like both Excel and Mathcad).
Definitely not the most interesting aspect of the app, yet a very important one is the GUI. It's designed to feel like a traditional word processor. However, by pressing the equals sign opens up a formula processor in a spreadsheet. Just like in the case of spreadsheet apps, the formulas update instantly once the numbers change.
Engineers will definitely appreciate features such as the so-called "units intelligence," variable names, matrix math, and the ability to add custom functions. The app can also load previous work and things are even easier since it supports a wide range of files, Excel files, and PDFs being just a few examples.
For users familiar with both Excel and Mathcad, getting started with the app might be quite easy, however, beginners should take the time to check out the official guides on equations, units, spreadsheets, sketches, and equation solving. There's also a very useful and comprehensive Table of Contents section worth checking out.

System requirements

Limitations in the unregistered version