Integrate an achievement system: introduce badges, levels, and milestones to reward users and gamify their learning experience.

Integrate statistics: add a statistics page to help users track their progress, quiz performance, and improvement trends.

Promote the app: focus on expanding the user base through social media, influencer partnerships, and targeted campaigns.

Gather feedback: implement a feedback system to continuously improve the app based on user input.

Multilingual support: add multiple language options to make the app more accessible and inclusive for a global audience.

Leaderboards and social sharing: introduce leaderboards and the ability to share achievements on social media for increased engagement.

Multiplayer mode and geolocation challenge: add real-time multiplayer quizzes and a geolocation challenge for a more interactive experience.