Definitions of terminology used by Sensor Tower

Sensor Tower Glossary

Here you can get a full list of all of our definitions throughout the platform. 

App Intelligence

  • Traffic Score
    The Traffic Score determines how often this specific keyword is searched for within a given app store. A higher Traffic Score means more people are searching for this term and more people will see the apps that rank for this keyword. The Traffic Score is on a logarithmic scale (base 10) from 0 to 10, with 10 being the most traffic.
  • Difficulty Score
    The Difficulty Score determines how hard it is for an app to be ranked at the top for this keyword. A lower Difficulty Score means it will be easier to rank in the top search results when this keyword is searched. The difficulty score is on a logarithmic scale (base 10) from 0 to 10, with 10 being the most difficult.
  • Keyword Downloads
    Keyword Downloads is an Enterprise App Intel product that estimates the downloads an app earns from all the keywords it ranks for.
  • Apple Search Ads ​​​​​
    Apple Search Ads allows you to bid on the top spot for any Keyword’s Search Results whenever a user searches for an app within the App Store.

My Sales Metrics and My App Analytics

Apple App Store Metrics

  • Product Page Views
    The number of times your app’s product page has been viewed on a device using iOS 8 or later on the Apple App Store.​​​​​
  • App Store Impressions
    The number of times your app was viewed in the Featured, Categories, Top Charts, and Search sections of the Apple App Store. This metric includes Product Page Views.
  • App Units
    The number of first-time app downloads made on the App Store using iOS 8 or later. App Units do not include app updates, downloads from the same Apple ID onto other devices, and re-downloads to the same device. (App Units match up with Sensor Tower’s “Downloads” Metric)
  • Paying Users
    The number of unique users, based on Apple ID, that paid for an app or an In-App Purchase.
  • Installations
    The total number of times your app has been installed on devices with iOS 8 or later. This metric includes re-downloads on the same device, downloads to multiple devices sharing the same Apple ID, and Family Sharing installations. Totals are based on app users who agree to share their data with you.
  • Sessions
    The number of times the app has been used for at least two seconds. If the app is in the background and is later used again, that counts as another, separate session. Totals are based on app users who agree to share their data with you.
  • Active Devices
    The number of devices with at least one session during the selected period and is based on devices running iOS 8 or later. Totals are based on app users who agree to share their data with you.
  • In-App Purchases
    The total number of purchases a user has made on your app. (Please view our definition of Revenue for a full definition of Revenue.)

Google Play Metrics

  • Installs on Active Devices
    Number of Android devices that have been online at least once in the past 30 days that have your app installed.
  • Installs by Device
    Number of devices that users install your app on for the first time. This is NOT the metric that is synonymous with the download metric, as we only attribute first time installs by a user, not the device.
  • Uninstalls by Device
    Number of devices that uninstall your app.
  • Upgrades by Device
    Number of devices that install an update for your app.
    Installs by Users: Unique users who installed the app on one or more of their devices for the first time. This metric is synonymous with the “Download” metric on the Sensor Tower Platform.
  • Uninstalls by user
    The number of times unique users have uninstalled the app from all of their devices.
  • Install events
    How many times the app has been installed on a device, including devices that previously uninstalled your app and are installing it again.
  • Update events
    How many times the app has been updated.
  • Installs by user
    Unique users per country who installed the app on one or more of their devices for the first time.

Store Intelligence

  • Download
    The Download metric that is tracked in our Store Intelligence platform is the unique download per iOS or Google Play account.
  • Revenue
    Sensor Tower utilizes Net Revenue as our metric for measuring app earnings. Our App Store and Google Play revenue is Net; as estimates reflect app's gross revenue minus 30%, which is the base amount Apple and Google take from all app purchases. Our revenue estimates include spending on paid apps, in-app purchases, and in-app subscriptions.
  • Revenue Per Download (RPD)
    Revenue Per Download (RPD) is a measurement of an app’s performance available in App Analysis of Store Intelligence. RPD represents cumulative revenue divided by cumulative downloads, or simply put: RPD is the average revenue that an app earns per download.
  • Align by Launch
    Align by Launch is a feature of Store Intel App Analysis. It is a data visualization option that shows Revenue, Downloads, or Revenue Per Download, aligned with each app's worldwide launch day.
  • Average Revenue Per Download (ARPDAU)
    Average Revenue Per Daily Average User (ARPDAU) is a measure of how successfully an app monetizes it's active users. ARPDAU calculations take the total revenue over a period and divides revenue by the active users over the same period.
    At a daily granularity: ARPDAU = Revenue earned on a day / Active users on a day

Ad Intelligence

  • Impression
    One impression refers to a single time an ad is shown on another app. Specifically, another app because we only capture ads for mobile apps. We do not capture brand ads that do not direct the user to specific app.
  • Network
    Sensor Tower captures ads from multiple different Ad Networks in Ad Intelligence. Ad Networks are the companies that work with both Ad Advertisers and Ad Publishers to share ads between them. Ad Networks work as the middlemen between Advertisers and Publishers to make sure that the ads are shown on the best publishers for the ad.
  • Share of Voice (SOV)
    Sensor Tower utilizes Share of Voice (SOV) as our metric for measuring the percentage of impressions an advertiser has from the total number of impressions sent from an ad network and the number of impressions sent to a publisher from a selected ad network
  • Ad Advertiser
    Within Ad Intelligence, Sensor Tower defines advertisers as apps that are running mobile ad campaigns on iOS or Android within our selected networks.
  • Ad Publisher
    Within Ad Intelligence, Sensor Tower defines publishers as the apps that are monetizing their platform by displaying ads to their users.

Usage Intelligence

  • Active User
    We define an Active User as any phone user that has at least one session in a specific time period. If a user has more than one session in the selected time period, they will still only count as one Active User for that time period. Sensor Tower breaks out these Active Users into three separate time periods stated below, Daily, Weekly, and Monthly Active Users.

Session Metrics

  • Session
    A Session defined by Apple is anytime a user brings an app to the foreground of the phone for more than 2 seconds. A session concludes when the user navigates completely away from the app, to the home screen or another app (the app is no longer in the foreground).
    A Session defined by Google is anytime a user brings an app to the foreground of the phone for more than 2 seconds, however, the session is closed as soon as the app launcher is opened. (This typically causes Google to have more sessions, however, the sessions will slightly shorter than Apple's.)
  • Session Count
    The Session Count metric illustrates how often users have a Session on the application per day, week, or month. In the platform, this is denoted in a percentage which shows what percent of users are using the app once a day, twice a day, three times a day, etc.
  • Session Duration
    The Session Duration metric shows the average of how long users are within each Session. The first column of Session Duration shows the time period from “0-3 seconds,” however because a Session must be more than 2 seconds to count as a Session, this column shows Sessions from 2 to 3 seconds.
  • Time Spent
    The Time Spent metric is a combination of the Session Count and Session Duration metrics. It will show the overall average amount of time that the user spends within an application over the selected time period (Day/week/month). This will include the duration of all sessions rather than just the duration of a single session.
  • Retention
    Daily retention is defined as the number of active devices on day X / active devices during the entire retention period. ​
  • Active devices on day X
    The number of unique devices with at least one session on day "X" during the selected retention period.
  • Active devices during the entire retention period
    Total number of active devices where the user has at least one session throughout the entire retention period.
    Retention = number of active devices on day X / total active devices during the entire retention period
    For example, if an app was first downloaded 120 users on May 1st and after 90 days, 100 of those users opened an app at least once, their 100 devices become 100 active devices (The leftover 20 are taken out).
    If 30 of these user’s active devices log a session with the on May 8th (7 days after the initial download) then the retention will be 30% on day 7.
    Note: Day 0 = May 1st, Day 1 = May 2nd, Day 2 = May 4rd, Day 3 = May 4th, Day 7 = May 8th and so on. Our definition matches Apple's definition.
  • Demographics
    Our Demographics metric measures the ages and gender breakups of an application’s users. We spilt these ages ranges up into 18–24, 25–34, 35–44, 45–54, and 55+.
  • Increased Chance of Use
    The Increased Chance of Use metric shows how more likely an app is to be used by these users compared to the typical user. If the typical user has a 20% chance of using an app but has Increased Chance of Use of 10%, that user now has a 30% chance of using that app.


  • Soft Launched App
    A Soft Launched app is any app that hasn't been fully released to the global market and is still being 'tested' in specific markets. Our Global Fields section can provide more information towards how we organize these apps.

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