--- title: About App Metrics Library, Made by Linkrunner description: App Metrics Library is made by Linkrunner, the MMP for app growth teams. How formulas are chosen, why calculator inputs are examples, and how to report errors. url: https://appmetricslibrary.com/about/ --- # About App Metrics Library What the library covers, how formulas are chosen, and what the calculator inputs are. **Short answer** App Metrics Library is a reference of 35 mobile app metrics. Every entry has a one-sentence definition, the standard formula and its common variants, and a calculator that runs in your browser with example inputs you replace with your own. Method ## How is the library put together? ### What it covers 35 metrics across acquisition, activation, engagement, retention, monetisation and virality, plus the north star metric; four vertical hubs (EdTech, fintech, OTT and streaming, gaming); and four comparisons of metrics that are often confused. ### How formulas are chosen - Each entry uses the most common formula as its headline. - Where definitions differ between tools or teams (for example LTV, churn, retention and DAU/MAU), the variants are shown in a table with when to use each. - Calculators use exactly the formulas shown on the page, and the same expressions are checked in Python and in the browser. ### About the example inputs Every calculator loads with example inputs so it shows a worked answer. **They are not benchmarks, averages or targets.** Replace them with your own numbers. Money examples are in US dollars. Every formula works in any currency, so you can enter your own figures in the currency you report in. ### Benchmarks The site quotes very few benchmark figures. Where it does, it names the published report the figure comes from and links to a page that shows its range. No figure is presented as a target. ### Privacy Calculators run entirely in your browser. Nothing you type is stored or sent. Linkrunner ## Who makes this site **App Metrics Library is made by [Linkrunner](https://www.linkrunner.io/?utm_source=appmetricslibrary&utm_medium=referral&utm_campaign=about&utm_content=about).** Linkrunner made the library so app teams can define and calculate metrics consistently, with the same formula behind a number whichever tool reports it. The formulas and calculators work the same whichever MMP or analytics tool you use. ### What Linkrunner is - An AI-driven mobile measurement partner (MMP) that unifies attribution, deep linking and SKAN in one platform. - Used by 400+ apps. - A free plan with 25k one-time attributed installs, no credit card needed and every feature included. - After that, postpaid pay-as-you-go pricing from $0.012 per attributed install, falling at higher volumes. See [pricing](https://linkrunner.io/pricing?utm_source=appmetricslibrary&utm_medium=referral&utm_campaign=about&utm_content=about). ### Where to go next - [Linkrunner website](https://www.linkrunner.io/?utm_source=appmetricslibrary&utm_medium=referral&utm_campaign=about&utm_content=about) - [Linkrunner docs](https://docs.linkrunner.io/introduction?utm_source=appmetricslibrary&utm_medium=referral&utm_campaign=about&utm_content=about) - [Linkrunner blog](https://linkrunner.io/blog?utm_source=appmetricslibrary&utm_medium=referral&utm_campaign=about&utm_content=about) - [Book a demo](https://linkrunner.io/contact?intent=demo&utm_source=appmetricslibrary&utm_medium=referral&utm_campaign=about&utm_content=about) ### Metrics that Matter Linkrunner's blog series on the metrics each kind of app should track: - [Metrics that Matter: EdTech](https://linkrunner.io/blog/metrics-that-matter-edtech-edition?utm_source=appmetricslibrary&utm_medium=referral&utm_campaign=about&utm_content=about) - [Metrics that Matter: Fintech](https://linkrunner.io/blog/metrics-that-matter-fintech-edition?utm_source=appmetricslibrary&utm_medium=referral&utm_campaign=about&utm_content=about) - [Metrics that Matter: OTT and streaming](https://linkrunner.io/blog/metrics-that-matter-ott-media-streaming-edition?utm_source=appmetricslibrary&utm_medium=referral&utm_campaign=about&utm_content=about) - [Metrics that Matter: Mobile gaming](https://linkrunner.io/blog/metrics-that-matter-mobile-gaming-edition?utm_source=appmetricslibrary&utm_medium=referral&utm_campaign=about&utm_content=about) [Create a free account (25k installs free)](https://dashboard.linkrunner.io/sign-in?utm_source=appmetricslibrary&utm_medium=referral&utm_campaign=about&utm_content=about) Contact ## Corrections Spotted an error or a definition that has changed? Email [hello@appmetricslibrary.com](mailto:hello@appmetricslibrary.com) with the page and a source. FAQ ## Questions **Where do the formulas come from?** From standard industry usage, checked against public definitions. Where tools or teams define a metric differently, each entry shows the variants side by side instead of picking one silently. **Are any of the numbers on this site benchmarks?** Calculator inputs are examples only. The few benchmark figures on the site name the published report they come from, and none are presented as targets. **How do I report a mistake?** Email hello@appmetricslibrary.com with the page and what should change. Corrections to formulas are made against a public source. **Who makes App Metrics Library?** Linkrunner, the mobile measurement partner (MMP) for app growth teams. Linkrunner made the library so teams can define and calculate app metrics consistently; the formulas and calculators work the same whichever tools you use. **Does the calculator send my numbers anywhere?** No. It runs entirely in your browser, and nothing you type is stored or sent anywhere.