Multi-Calculator App with Instant Results for Everyday Math Tasks
People reach for calculator apps dozens of times daily for unit conversions, tip splits, percentage discounts, and loan payments. on.equals on IH packages every common calculator into one app with results-before-you-finish-typing UX ($300/month revenue). The opportunity is a calculator app that replaces 3-5 utility apps.
Problem Statement
A user needs to split a restaurant bill among 4 people, including tax and tip. They open the native calculator, compute the subtotal per person, then open a tip calculator app for the tip amount, then do mental math for the total. Two apps and 3 minutes later, they have a number that might be wrong. Next day they need to convert 200 EUR to USD, opening yet another app. Each micro-task is simple, but switching between purpose-built utility apps creates friction that accumulates across dozens of daily calculations.
The Idea
A single calculator app that handles tip splitting, unit conversion, loan payments, percentage calculations, and currency conversion — with results appearing as you type, not after you press equals.
Why Now
Native phone calculators remain basic (no unit conversion, no tip splitting). Users install 3-5 separate utility apps for everyday math. The on.equals approach of showing results before typing finishes mirrors modern search UX expectations.
Target User
Mobile-first consumers who perform 5+ everyday calculations per day across different calculation types
Target Market
Mobile utility apps and calculator tools
The full brief is free to read
Create a free account to unlock the complete build-ready brief for “Multi-Calculator App with Instant Results for Everyday Math Tasks”, including:
- MVP scope & feature boundaries
- Step-by-step validation plan
- Score rationale across 11 dimensions
- Monetization model & pricing angle
- Competitors with links
- Acquisition channels & go-to-market
- Risks & counter-evidence
More Productivity opportunities
Custom Analytics Dashboard and Report Builder for Notion Projects Power Users
Buyer reviews for Notion Projects consistently highlight reporting gap friction, specifically: Portfolio view is too basic, can't aggregate metrics across projects. No cross-; No Gantt chart with actual dependency arrows. Timeline view is decorative only , . This pain is concentrated among Project managers needing portfolio-level reporting from Notion Projects and creates demand for a focused tool that resolves the gap without requiring a platform switch. The Productivity category has matured enough that users have committed to Notion Projects as infrastructure, making adjacent tooling more viable than platform replacement.
View opportunityProductivityPerformance Monitor and Content Optimization Engine for Confluence Cloud
Buyer reviews for Atlassian Confluence consistently highlight performance issue friction, specifically: Search is unreliable, returns irrelevant results for exact page titles. CQL que; Confluence Cloud is noticeably slower than Server was. Page editing has 2-3 seco. This pain is concentrated among Teams experiencing Confluence Cloud performance issues with large knowledge bases and creates demand for a focused tool that resolves the gap without requiring a platform switch. The Productivity category has matured enough that users have committed to Atlassian Confluence as infrastructure, making adjacent tooling more viable than platform replacement.
View opportunityProductivityCloud Migration Assessment Tool and Data Center Transition Planner for Confluence
Buyer reviews for Confluence Data Center consistently highlight migration difficulty friction, specifically: Atlassian is ending Data Center support. Migration to Cloud loses our 15 custom ; 100,000+ pages need migration. Atlassian's migration tool handles content but no. This pain is concentrated among IT teams migrating from Confluence Data Center to Confluence Cloud and creates demand for a focused tool that resolves the gap without requiring a platform switch. The Productivity category has matured enough that users have committed to Confluence Data Center as infrastructure, making adjacent tooling more viable than platform replacement.
View opportunityProductivityIndustry-Specific Template Marketplace and Compliance Starter Kit for Notion
Buyer reviews for Notion Templates consistently highlight template shortage friction, specifically: No HIPAA-compliant project management templates. No healthcare-specific onboardi; Financial services compliance templates don't exist. SOX audit checklists, KYC p. This pain is concentrated among Teams needing industry-specific Notion templates for regulated workflows and creates demand for a focused tool that resolves the gap without requiring a platform switch. The Productivity category has matured enough that users have committed to Notion Templates as infrastructure, making adjacent tooling more viable than platform replacement.
View opportunityProductivityCross-Team Collaboration Layer and Shared Workspace Manager for Todoist
Buyer reviews for Todoist consistently highlight collaboration friction friction, specifically: Team features feel bolted on. Can't assign tasks across workspaces. No shared vi; No Gantt or timeline view for team planning. Dependencies are limited to premium. This pain is concentrated among Team leads using Todoist for shared project coordination across departments and creates demand for a focused tool that resolves the gap without requiring a platform switch. The Productivity category has matured enough that users have committed to Todoist as infrastructure, making adjacent tooling more viable than platform replacement.
View opportunityProductivityFeedback-to-Development Pipeline Bridge and Prioritization Sync for Pendo
Buyer reviews for Pendo Feedback consistently highlight integration gap friction, specifically: Feedback items don't sync to Jira or Linear automatically. Product decisions hap; Customer feedback can't be linked to Salesforce opportunity data. Sales wants to. This pain is concentrated among Product teams connecting Pendo Feedback with development workflow tools and creates demand for a focused tool that resolves the gap without requiring a platform switch. The Productivity category has matured enough that users have committed to Pendo Feedback as infrastructure, making adjacent tooling more viable than platform replacement.
View opportunity