Grammar Checking App Business Success Stories [2026]

In this list, you'll find real-world grammar checking app business success stories and very profitable examples of starting a grammar checking app business that makes money.

1. InstaText ($600K/year)

Matej Guid, CEO and co-founder of InstaText, came up with the idea for his AI-based online writing assistant while working as a professor and struggling with editing academic papers. Leveraging advances in AI, Guid and his team created a tool that uses reinforcement learning to continuously improve text, resulting in over half a million active users and more than $50k in monthly revenue in just two years. InstaText was even named the Slovenian Startup of the Year in 2020.

How much money it makes: $600K/year
How much did it cost to start: $50K
How many people on the team: 4

Our AI Writing Tool Won 'Startup Of The Year' And Has Customers In More Than 150 Countries

InstaText is an AI-based online writing assistant that helps non-native speakers improve their English, with over half a million active users from 150 countries worldwide, bootstrapped from $0 to $50k monthly revenue in two years and quadrupled their sales in 2021, becoming Slovenian Startup of the Year and expanding to web applications and browser extensions.

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