In spring 2026, I built a wallpaper app prototype in Rork with one specific goal: to test whether the AdMob integration it generates holds up against twelve years of ad-revenue development experience.
I've been building mobile apps independently since 2014. My portfolio spans wallpaper apps, ambient sound apps, and manifestation tools — titles that together have crossed 50 million cumulative downloads. At peak, my AdMob revenue cleared the equivalent of $10,000 in a single month. That history gives me strong opinions about the implementation details that actually move revenue numbers.
This isn't a guide on how to use Rork. It's a record of what I found when I tested its AdMob output against what I know from a decade-plus of doing this for real. I'm writing it because I couldn't find a developer-to-developer account anywhere — just marketing copy and generic tutorials that don't address the revenue-layer details.
The Setup — Keeping It Comparable
I deliberately kept the prototype minimal so the comparison was clean. A vertical-scroll image viewer where every fifth scroll triggers an interstitial ad, and a long-press save triggers a rewarded ad before writing the image to the camera roll. This is standard ad placement for the wallpaper genre. I've shipped this exact flow multiple times across different stacks — bare React Native, Expo SDK, and now Rork — which made the comparison meaningful.
My Rork prompt was:
Create a wallpaper browsing app with vertical image scrolling.
Add an interstitial ad after every 5 images using AdMob.
Add a rewarded ad when the user saves an image.
Use AdMob test IDs.
The generated code selected react-native-google-mobile-ads over the older expo-ads-admob. That's the right choice in 2026 — the newer SDK has better performance and active maintenance. I was prepared to be underwhelmed and wasn't, at least not on this initial point.
Concern #1 — Ad Timing Logic Is Naive
The interstitial trigger used a simple counter: track scroll events, fire an ad on every fifth one.
// Rork-generated logic (simplified)
const [scrollCount, setScrollCount] = useState(0);
const handleScroll = () => {
const newCount = scrollCount + 1;
setScrollCount(newCount);
if (newCount % 5 === 0) {
showInterstitial();
}
};This works in a test environment. Under real user behavior, it causes problems that are hard to diagnose later. A fast scroller can trigger three or four interstitials within a minute. Google's ad policies address excessive ad density explicitly, and Play Store reviews surface it quickly. More importantly for revenue: high ad frequency without session-length throttling degrades day-7 retention, which reduces lifetime revenue even when short-term impression counts look fine on the AdMob dashboard.
The timing logic I actually deploy combines a minimum session elapsed time with a minimum cooldown between ads:
const MIN_SESSION_SECONDS = 30;
const MIN_AD_INTERVAL_SECONDS = 45;
const sessionStart = useRef(Date.now());
const lastAdTime = useRef(0);
const shouldShowInterstitial = () => {
const sessionAge = (Date.now() - sessionStart.current) / 1000;
const cooldown = (Date.now() - lastAdTime.current) / 1000;
return sessionAge >= MIN_SESSION_SECONDS && cooldown >= MIN_AD_INTERVAL_SECONDS;
};If you give Rork specific timing constraints in the prompt, it regenerates accordingly. The gap is that the default doesn't encode AdMob's implicit policy expectations — which is genuinely hard to know without having shipped several ad-supported apps and seen what gets flagged in practice.
Concern #2 — ATT Initialization Order Is Wrong
The App Tracking Transparency permission prompt appeared after MobileAds().initialize(). This ordering has revenue implications that don't surface as errors.
When the SDK initializes before ATT permission is granted, it begins serving non-personalized ads. Granting permission afterward often doesn't flip the serving mode to personalized within the same session. The result: users who consented to tracking still receive lower-value non-personalized ads, because the SDK's serving state was already locked at initialization.
// Wrong (Rork's generated sequence)
await MobileAds().initialize();
const { status } = await requestTrackingPermissionsAsync();
// Correct sequence
const { status } = await requestTrackingPermissionsAsync();
await MobileAds().initialize();No errors appear. The app runs normally. But I've measured 20–30% eCPM differences between correctly and incorrectly ordered initialization in the same app, under otherwise identical conditions. For a monetization-focused app, that's not a rounding error.
Concern #3 — No Environment Separation for Ad Unit IDs
The generated file hardcoded AdMob test IDs as string constants with no structure for managing production IDs.
// Rork-generated — no environment handling
const BANNER_AD_UNIT_ID = 'ca-app-pub-3940256099942544/6300978111';"Shipped to production with test IDs" happens. The fix is simple — app.config.js with environment variables routes test IDs in development and real IDs in production builds automatically — but it needs to be added before the build habit forms.
// app.config.js
export default {
extra: {
admobBannerId: process.env.ADMOB_BANNER_ID ?? 'ca-app-pub-3940256099942544/6300978111',
},
};I added this structure before continuing the test. For anyone building a Rork AdMob app, setting this up early saves a confusing revenue report later.
The Genuine Win — Rewarded Ad UX Was Solid
The rewarded ad flow was better than I expected — worth saying clearly.
The generated code used event listeners correctly, ran the save operation on EARNED_REWARD, showed a confirmation notification, and included a fallback path for when no ad was available to show.
// Generated rewarded ad flow (simplified)
const handleSaveWithReward = async () => {
if (!rewardedAdLoaded) {
await saveImageToGallery(imageUri);
return;
}
try {
await rewardedAd.show();
} catch (error) {
await saveImageToGallery(imageUri);
}
};
rewardedAd.addAdEventListener(RewardedAdEventType.EARNED_REWARD, async () => {
await saveImageToGallery(imageUri);
showSuccessNotification('Image saved!');
});Rewarded ads fail to load more often than developers expect — regional fill rates vary significantly, network conditions matter, and frequency caps arrive earlier than users realize. Apps that don't handle unavailable ads gracefully produce frustrated users and negative reviews. Rork handled the fallback correctly by default. That's the kind of thing that takes a production incident to learn if you encounter it for the first time on a live app.
What I Actually Changed
To be specific about the lift required: I fixed the ATT initialization order (five minutes), added environment variable routing for ad IDs (ten minutes), and replaced the scroll-count trigger with session-plus-cooldown timing logic (about thirty minutes including device testing).
Everything else in the generated code was usable without modification. App structure, data flow, image handling, navigation — none of that required rework for this prototype. The ad-specific changes were the only meaningful intervention, and the total time spent on modifications was well under two hours. That's a better ratio than I expected, and it reframed how I think about using Rork for this category of app.
For context: the equivalent from-scratch implementation in bare React Native, setting up the project from scratch, would realistically take a day or more, not counting testing. Rork compressed that to a few hours, even accounting for the review step.
Who This Works For
My overall assessment: Rork is a good starting point for AdMob monetization if you bring some baseline AdMob knowledge to the review process.
If you can check ATT ordering, ad timing logic, and ID management, the speed advantage is real. Build the functional skeleton in a few hours, review and adjust the revenue layer in under two hours. That ratio is worth taking for anyone who wants to prototype quickly and iterate.
If you're new to AdMob and planning to ship Rork's output without modification, the risks are quiet but cumulative. No single issue crashes the app, but all three concerns I described will quietly underperform against the potential of the same codebase with proper implementation. The gaps aren't obvious until you've seen them cost real revenue.
My current workflow: Rork for the functional skeleton, experience-based review for the revenue layer. For wallpaper apps and similar ad-supported formats, that combination is working well.
The complete AdMob implementation guide for Rork apps covers the full setup steps. Reading it alongside these three concerns gives you a clearer picture of what to verify before shipping.
I hope this record is useful for anyone building ad-supported apps with Rork — especially those earlier in the AdMob learning curve than I was when I first ran into these same patterns.