CheerUp Mini

I felt that I also needed firsthand experience creating and releasing a product. I wanted to understand more than just development work itself. I wanted to personally experience the process of uploading a completed app to the stores, releasing it, and seeing how people responded to the released app.

The goal was not to generate significant revenue right away or to build a highly polished service. Rather, I believed that understanding not only technical skills as a developer but also the process of looking at a product from a business perspective and taking it through release would clearly contribute to my growth.

The goals of this project were as follows.

Because this was my first app development project, I chose an app with relatively simple functionality. Rather than an app that required a server or payment features, it was an app with a simple screen structure that displayed phrases together with background images. I thought it would be enough if the app allowed me to learn Flutter app development and experience the full process of submitting an app to the app stores. Flutter is known as a framework that can create apps for multiple platforms from a single codebase, and it can be used to develop apps that support both Android and iOS [Flutter Official Website].

The idea itself began simply. I wanted to create an app that gathered and displayed words that give people strength, words of encouragement, and positive phrases. I thought it would be nice if someone could open the app even briefly during the day and see a positive sentence. I also wanted to make it more than just a list of phrases by turning it into an app like a digital photo frame, where the phrase and background automatically change when the screen is left on.

Setting the Development Goals

The goal of "CheerUp Mini" was to carry out a mobile app project that would let me experience the process all the way through an actual store release.

I clearly limited the feature scope from the beginning. I excluded features that would increase release difficulty, such as a server, login, and payments, and focused on experiencing the basic mobile app development flow and deployment process from start to finish.

The core concept of the project was “an app for enjoying short encouraging phrases like a digital photo frame.” I planned it so that when the user left the app open, the phrases and background images would switch automatically.

System Architecture

"CheerUp Mini" runs without a separate server. Phrase data and image resources are included inside the app, and the app combines and displays them on the screen.

Core Implementation Flow

Applying AdMob and Responding to Ad Review

Applying AdMob did not end with simply adding ad code. I experienced having my AdMob account temporarily suspended for about a week.

In AdMob, an app can be registered while unpublished and ad units can be created in advance, but app verification is only possible after the app has been released on a store. Google’s official documentation also explains that an app must be linked to a supported store to be reviewed, and that ad serving may be limited during review [AdMob - About app readiness].

Before the app was released, real ads were displayed during the store review process. Possibly because of this, my AdMob account was temporarily suspended. I cannot determine the exact reason for the suspension, but I learned that during the development and release stages, it is essential to check the use of test ads, whether app verification has been completed, and the ad serving restriction status. Google also advises developers to use test ads instead of real ads during development and explains that clicking real ads can cause an account to be flagged for invalid activity [AdMob - How you can prevent invalid activity].

Store Deployment Process and Issue Handling

"CheerUp Mini" was developed with the goal of deploying it on both iOS and Android.

The iOS release was handled through App Store Connect [Apple Developer - App Store Connect], and by following the required process, I was able to release it without any issues.

Google Play requires new personal developer accounts to meet closed testing requirements before a production release. At the time, the official documentation required at least 20 testers to participate for 14 consecutive days (currently, at least 12 testers are required). When applying for production access, developers also need to answer questions about the app’s testing process and release readiness [Goole Play - App testing requirements for new personal developer accounts].

The first application was not approved, so during the next closed test, I focused on communicating with testers, collecting and reviewing user feedback, and reflecting user feedback. Google Play’s closed testing guidance also recommends testing with specific users, providing a feedback channel, and collecting private feedback [Goole Play - App testing requirements for new personal developer accounts].

A different issue occurred during the second production access application. When I tried to submit the application questionnaire, "An unexpected error occurred. Please try again later." this message kept appearing, so the submission could not proceed. This error did not occur only in my environment. Stack Overflow also contains cases where, during production deployment or publishing in Google Play Console, “An unexpected error occurred. Please try again later” the error was reported by other users [Stack Overflow - what is this error "An unexpected error occurred. Please try again later. (8869003)"].

I handled the error step by step.

Changing browsers, clearing cookies and cache, using incognito mode, checking the VPN, and other client-side variables were eliminated first. Since the issue still was not resolved, I contacted Google Play support and sent a video reproducing the error. However, even after following the suggested steps, the issue was not resolved, so Google Play support replied that I was told it would be reported to the development team. I was told to try again after Google Play Console was updated, but the issue still was not resolved. In the end, the app remained unreleased on Google Play.