How to create custom events on Firebase for Android and iOS

Tracking unique interactions to optimise app performance

Firebase Analytics allows you to track predefined events such as app installations, updates or in-app purchases. These are automatically collected and are essential to provide basic user data.

With Firebase, it’s also possible to create custom events, which can help map out the actions that are unique to an app’s user interactions and respond to the optimisation needs of specific campaigns.

In the following sections, you will find out how to monitor user quality, engagement and retention by creating two key custom events:

• App opened X times in X days (following app_open frequency)
• Reached X Level (marking when users reach a new level within an app)
  

For each event, we are going to provide the code that needs to be executed for Android and iOS and tailor it to different programming languages.

Both App opened X times in X days and Reached X Level have the goal of encouraging the algorithm to find active users rather than installers. In fact, on platforms like Google and TikTok, for example, setting the number of installations as the primary metric of success means targeting not only engaged users but also low-quality customers who might have downloaded the app but never 
opened it again.

Reactions to advertisements can vary significantly: what catches one person’s attention might not resonate with another and quick installations following ad exposure don’t always translate into continued engagement. Often, the journey begins with users downloading an app out of curiosity, only to realise that it doesn't align with their interests.

For instance, Kurve ran successful campaigns for our clients Treecard and Sweatcoin, managing to drive growth at a very competitive cost per install. The next challenge was then to retain new users to ensure the effectiveness of these strategies over time.

By using Firebase custom events for Google Ads we were able to track engaged installations and improve retention.

Read on to find out how we achieved this. 

Firebase custom events step by step

App opened X times in X days

Tracking the frequency of app opens provides insights into engagement levels and can help determine user quality and increase retention. 

To promote our client Treecard’s Walk to Plant initiative, we tracked users who launched the app three times within a week and five times in fourteen days. This helped us direct the algorithm to people who were more likely to engage with the app, for example, dog walkers or fitness enthusiasts. Setting this metric as our benchmark for success in Google Ads enabled us to optimise our campaigns effectively.

Here are the three main steps to create an app_open custom event on Firebase:

1. Set up Firebase tracking for all important events in the app
2. Integrate Firebase with Bigquery
3. Write and run SQL query in Bigquery

1. Set up Firebase tracking for app_open events in the app

This step involves modifying the app's code to ensure that an app_open event is captured and sent to Firebase Analytics every time a user opens the app.

Android tracking

Below is the code to be executed to implement the logEvent() method and it includes two key parameters:

• level: indicates the level the user has reached and it shows their progression within the app;
• character represents the character the user was playing when the level_up event happened and it provides insights on the character’s popularity and user preferences.

Android tracking