For startups, subscription apps and commerce apps.
Mobile app CRO and optimisation. More customers for every euro spent.
More users who finish onboarding, come back and subscribe. I find the screen where they drop off, from the store listing to the paywall.
5/5 on Google, 3 reviews
Sébastien Balieu, your personal contact from start to finish.
The signs of an app that's losing its users.
Every install cost you a campaign, a carefully built store listing or months of word of mouth. A user who never opens the app again takes that spend with them.
My store listing gets views, but few installs
To test: the icon, the first three screenshots and the subtitle, then the reviews, read to find the objections.
My users drop out during onboarding
To test: remove the screens that delay the first result, and ask users to create an account after their first useful action.
They install, then never come back the next day
To test: get every new user to a first result in their first session, then send a useful notification the next day.
Few free trials turn into subscriptions
To test: when the paywall appears, how long the trial lasts and the order of the plans.
My users turn down notifications
To test: ask for permission at the moment it's useful, with one sentence that says what it's for.
I don't know which screen they drop off at
To test: track every step in Firebase, Mixpanel or PostHog, then read retention by cohort at D1, D7 and D30.
Recognise these signs in your app?
Get your free auditHarmonia, 60% 30-day retention among its subscribers.
Harmonia, the app I publish on the App Store and Google Play, helps families keep track of children's chores and rewards. The parent creates a task or awards points in a few seconds, and the child sees their progress and the reward they're working towards.
The work covered the store listing, onboarding and the move to the paid plan. The figures below come from App Store Connect and compare the 30 days to 26 October 2026 with the previous 30 days.
- +122% first-time downloads
- 5.08% store listing conversion, +13.9%
- +467% in-app purchases
- +156% revenue
From the store listing to renewal.
I put in place the fixes for your blockers, in order of their effect on retention and subscriptions.
In-app tracking
I set up the key events in Firebase, Mixpanel, Amplitude or PostHog, from install to purchase, so you can follow each cohort.
Store listing
The icon, screenshots, subtitle and rating, tested with App Store and Google Play experiments.
Onboarding
Fewer screens before the first result, account creation at the right moment, and the store listing's promise kept from the first session.
Activation
I find the action that brings your users back, then shorten the path to it.
Paywall and subscriptions
When it appears, trial length, plan order and copy, tested with RevenueCat, Adapty or Superwall.
Reviews and ratings
The rating prompt at the right moment, and negative reviews read one by one to find the friction.
UX/UI
I redesign the screens that hold users back. You approve each Figma mockup before development.
Notifications and reminders
Notifications and emails triggered by usage, to bring inactive users back.
Which screen should you fix first? The audit ranks the blockers by their effect on retention and subscriptions.
Get your free audit
Native or hybrid, even custom-built.
Blockers come from user behaviour. An onboarding that runs too long or a badly placed paywall holds users back the same way in a native, Flutter or React Native app. I read your data in the tool you already use.
iOSNative
AndroidNative
FlutterHybrid
React NativeHybrid
IonicHybrid
ExpoHybrid
FirebaseAnalytics
AmplitudeAnalytics
MixpanelAnalytics
PostHogAnalytics
RevenueCatSubscriptions
AdaptySubscriptions
SuperwallSubscriptions
App StoreStore
Google PlayStore
Custom-builtYour code
Five steps, from store listing to report.
From the first launch of your app to the monthly retention report.
Step 130 min · freeThe free audit
I install your app on iPhone and Android and go through it as a new user, from the store listing to the paywall. Within 48 working hours, you have around ten blockers, each with a screenshot and its fix.
Step 21 to 2 weeksTracking first
I check that every step reaches your analytics tool, from install to subscription, and that the retention cohorts are reliable.
Step 31 meetingPriorities
I rank each improvement by its expected effect on retention and subscriptions and by the development effort it needs. You know which screens come first.
Step 42 to 6 weeksImplementation
Your mobile team, your agency or my partners build the changes, with me leading the project. When volume allows, each change goes through a test, in the stores or in your subscription tool.
Step 5Every monthFollow-up
A monthly report on the work done and its effect on activation, D1, D7 and D30 retention and subscriptions, compared with the starting point.
For the audit, all I need is your app's link.
Start with the free auditCommitments before you sign.
They apply from the audit of your app onwards.
Before you sign
- I install and analyse your app myself.
- The audit only needs the App Store or Google Play link. I don't need access to your data.
- The audit report is yours to keep, even if we go no further.
- If the problem lies in the product, the market or a lack of users, I tell you, and I don't offer you ongoing support.
During the engagement
- I improve the existing screens first, before any talk of a redesign.
- Every mockup goes through you before development.
- Every change is compared with the starting cohorts.
- The report shows the winning tests and the ones that had no effect.
- I stay your contact, from the audit to the last report.
Send your app's link, the audit is free.
Get your free auditI grow my own app.
I was head of digital marketing at Walibi, then at Zetes. I founded a web agency in Brussels, then co-founded Coddy, escape games played on smartphones in 9 countries.
I also publish Harmonia, a family app on the App Store and Google Play. Onboarding flows, paywalls and retention cohorts are part of my daily work, and I audit every app myself.
20 years
in digital marketing, since 2006
250,000+
Coddy players, on their smartphones
+156%
revenue for Harmonia in one month
48 h
to audit your app, from store listing to paywall
5.0 out of 5
3 Google reviews
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The questions app publishers ask most often.
Can't find your question?Ask me directly
Find the blockers in your app.
Send your app's link. Within 48 working hours, you receive around ten blockers, from the store listing to the paywall, ranked by their effect on retention and subscriptions. The report is yours to keep, even if we go no further.
Get your free audit