Official Annotations are helpful insights that can explain spikes or sudden shifts in an app’s performance or give additional context to an app’s history. For example, Official Annotations can help explain:

  • Spikes in downloads that HBO apps experienced every time a new season of Game of Thrones was released.

  • Spikes in revenue that Fortnite experiences whenever a new season begins.

  • Why Pokémon Go suddenly started topping the Strategy game rankings in Summer 2019.


Our goal is to expose helpful new data alongside our existing graphs that give additional context to the primary signals that are being measured. You’ll see Official Annotations represented as text comment icons along the bottom of the graphs on App Analysis (Store Intel) and Category Rankings (App Intel). Official Annotations are the same color as the app they belong to, and are aligned to the same date timeline as the primary graph. To display the details of an Official Annotation, simply hover over the icon.



Use Cases

Sensor Tower has identified a wide range of signals that can help explain causality of consumer activity on mobile. We can measure app updates, mobile advertising, and App Store editorial choices that drive user acquisition, revenue, and engagement. But there are some important events that are outside of the mobile app ecosystem or can’t be measured by typical mechanisms, and this is where Official Annotations excels. 


Consider this spike in Unified Downloads for Snapchat in April 2019:

There’s no new advertising activity leading up to the spike, and the app updates around that time are bug fixes and the release of some social games. So what happened here? The primary driver of these downloads was almost certainly the release of the gender swap AR lens. To be more specific, the viral reaction of users sharing gender swapped selfies on social media, and subsequent news coverage generated consumer interest which drove new downloads.


You could also consider scenarios like live-ops events in games, which are primarily released through server-side changes, not app updates. Or consider the impact of live-streamed events, viral marketing, or film releases that drive licensed mobile apps. All these events are difficult to capture programmatically, but have an important impact on the downloads, revenue, and engagement that Sensor Tower provides.


Sensor Tower’s Mobile Insights team comes to the rescue with our new Official Annotations feature. Our expert industry analyst team will identify spikes and tie them to holistic external data and provide the key reasons why the movement occurred. We’ve explored company acquisitions, calendar events like the Super Bowl and Black Friday, and bespoke research around games seasons and content releases. 


Official Annotations are exposed on App Analysis (Store Intel) and Category Rankings (App Intel), along a new UI component called the Insights Timeline. Here’s an example of the annotation described above:

Over time, we’ll implement this feature across additional Sensor Tower products, and introduce new kinds of signals to the Insights Timeline. We’re excited to hear your feedback and any requests for new types of research and annotations.