ASO (App Store Optimization) on-page optimization refers to the process of optimizing your app’s metadata and elements within the app itself, to improve its visibility and ranking in the app store search results.

App title: Make sure your title includes one or two of your primary keywords, is unique and attention-grabbing.
Description: Use keywords in your description, but make sure they flow naturally and accurately describe your app.
Keywords: Choose relevant keywords and include them in your app’s metadata.
Screenshots and videos: Use screenshots and videos to showcase your app’s features and benefits.
Reviews and ratings: Encourage users to leave positive reviews and ratings, as these are a ranking factor in the app store.
App localization: Translate your app’s metadata and elements into different languages to reach a wider audience.
App update: Regularly update your app with new features and fix bugs to keep users engaged.

It is important to note that while on-page optimization is important, it is just one aspect of ASO. In order to achieve optimal results, it should be combined with off-page optimization techniques such as link building, social media promotion, etc. Additionally, following the guidelines and rules provided by the app stores is important to avoid any penalty or rejection of the app.