errProof is described as 'The website has a lot of useful and unique tools' and is an website in the Education & Reference category. There are more than 100 alternatives to errProof, not only websites but also apps for a variety of platforms, including Windows, Mac, Android and Linux. The best alternative is SpeedCrunch, which is both free and Open Source. Other great sites and apps similar to errProof are Wolfram Alpha (Freemium), Pastebin.com (Freemium), Qalculate! (Free, Open Source) and Write.as (Freemium, Open Source).
SpeedCrunch is a free, fast, high precision open source algebraic calculator with an intuitive interface and a extensive list of features, including: Unlimited Variables, Syntax Highlighting, Functions, with 'Automagic' Completion, 50 Decimal...
Wolfram Alpha is a "Computational Knowledge Engine" - different from a search engine, it answers factual queries directly by computing the answer from structured data, rather than providing a list of documents or web pages that might contain the answer.
The website is mainly used by programmers to store pieces of sources code or configuration information, but anyone is more than welcome to paste any type of text. The idea behind the site is to make it more convenient for people to share large amounts of text online.
Qalculate! is a multi-purpose cross-platform desktop calculator. It is simple to use but provides power and versatility normally reserved for complicated math packages, as well as useful tools for everyday needs (such as currency conversion and percent calculation).
Repl.it is a complete, collaborative cloud development environment in the browser featuring everything from linters and debuggers to third-party packages, hosting and deployment. FEATURES - Real-time collaborative code editing. - Live chat in the workspace.
A simple yet powerful calculator that includes standard, scientific, and programmer modes, as well as a unit converter. It's the perfect tool to add up a bill, convert measurements in a recipe or other project, or complete complex math, algebra, or geometry problems.
Ghostbin is a paste service, and I’m going to skip explaining precisely what that is—it’s fairly obvious. The real interesting questions are “why did you build it?” and “where did I get all these bees?”
Soulver is a smart notepad with a built-in calculator. It gives instant answers to any calculations it finds in your text. It's a better way to work stuff out than with a traditional calculator, and a more lightweight tool for quick calculations than a spreadsheet.