What it does
Calculator₊ is an all-in-one calculation and math-solving app for iOS. It goes far beyond a standard calculator by offering multiple input methods, including a camera-based photo solver for printed equations and a sketchpad for handwritten problems. The app also bundles a suite of specialized calculators for scientific functions, fractions, percentages, currency conversion, and unit conversion.
Where it shines
The app truly stands out with its flexible problem-solving capabilities. The photo solver, demonstrated at 01:25, makes quick work of textbook problems by scanning an equation and providing a detailed, step-by-step solution. Another impressive feature is the rich history management seen at 04:40, which allows users to tag, annotate, and favorite past calculations, turning a simple log into a powerful workspace for tracking homework or professional work. The math notes feature (07:24) further enhances this by providing a digital canvas for working through problems with an integrated solver.
UX highlights
- Multi-modal input: The app offers three distinct ways to enter a problem: keypad, photo scan (01:25), and handwritten sketch (02:52). This provides flexibility for various use cases.
- Interactive history: The history log is not just a list. It's a workspace where users can add colored tags (04:51), text notes (04:55), and favorites to organize their work.
- Integrated solvers: Both the photo and sketch inputs are connected to a powerful engine that provides not just the answer but also step-by-step solutions (01:46), which is great for learning.
- Smooth personalization: The onboarding flow (00:03) allows users to customize themes and button shapes, creating an immediate sense of ownership.
- Contextual calculator in notes: While in the math notes feature, users can pull up a calculator overlay (08:39) to perform quick calculations without leaving their workspace.
- Broad utility: The app includes a wide range of converters for currency (06:35), and various units like length, energy, and volume (06:58), making it a versatile tool.
Monetization & growth
The app presents a paywall early in the onboarding flow, immediately after personalization (00:28). It offers a 3-day free trial that converts to a weekly subscription. A key tactic is the use of a hidden, cheaper yearly plan accessible only via a subtle "View other plans" link (00:32). This anchors users on a higher price before revealing a more attractive offer. The app also employs a rating warm-up prompt (00:22) to gather positive reviews.
Who it’s for
This app is primarily for students, from middle school through college, who need help with homework and want to understand the steps to solve complex problems. It's also useful for engineers, scientists, and professionals who require a powerful, multi-function calculator with robust history and conversion tools on the go.
Notes & opportunities
The app's core functionality is strong, but the user experience could be refined. The monetization strategy feels slightly aggressive, with a paywall appearing before any core features are demonstrated. The hidden discount tactic (00:32) could be perceived as deceptive by some users. Furthermore, both the photo solver and sketch solver showed error or failure states during the recording (02:37, 04:15), suggesting the recognition technology may need more polishing to improve reliability.