What really works
Every announced feature is tested: working, partial or missing. You finally know where your product stands.
App audit · An independent view
Find out what your app is really worth.
Your app was built by a team, an agency, or with Lovable, Bolt or Claude Code. I check what really works, data protection, the code and the costs. You get a report written for a founder: what to keep, what to fix, what to replace, and in which order.
Free 15-minute call, no commitment. NDA available.
Jérémy MarquerFractional CTO · France and remote
- working days, usually, for the express assessment
- 3 days
- registered users on the apps I built
- 150,000+
- people managed in my teams
- 25+
- building and leading tech teams
- 10 years
01 / Who it is for
Your app exists, and you do not really know what it is worth
The audit helps you decide before spending more.
- 01
What was promised is not what works.
Your team or provider announces features, and you see a gap with what is delivered and usable. Before more development or new hires, you want an independent opinion.
- 02
Your app was generated with AI or no-code.
Lovable, Bolt, Base44, v0 or FlutterFlow helped you validate the idea. Before opening it to customers, check data security, backups and the cost at 10 times more users.
- 03
A provider is handing over, or leaving.
An agency or freelancer built the app. You want to know what it is worth, who holds the accounts and whether another team can take over the code.
02 / What I check
What I check in your app
Each point gets a green, amber or red light, with examples taken from your code.
Data security
Who can read or change what: database access rules, API keys exposed in the code, one customer’s data visible to another. For health or banking data, I also check where it is hosted and who can access it.
Code structure
Could another developer take over? File organisation, duplication, dependencies and fragile areas.
Account ownership
Who holds the accounts for the tool, the database, GitHub and the domain name? Everything should be in your name.
Backups and environments
Are there backups, a test version separate from production, and a way to roll back?
Monthly costs
Subscriptions, credits, database and third-party services: what the app costs today and at 10 times more users.
Tools covered
Lovable
Bolt- Base44
- FlutterFlow
v0
Replit
Cursor
Claude Code
Bubble
Same method for an app coded by hand or by an agency.
03 / Sample report
What your report looks like
One point per line, one light per point, and what to do. Readable by you and by your developer.
Audit report · Appointment booking appMade-up example
Point checkedStatusFindingNext step
What really worksAmber14 announced features: 9 working, 3 partial, 2 missing (PDF export, email reminders).Finish the 3 partial ones before adding more.
Data accessRedA signed-in user can read another user’s records: the table access rule is open.Fix first, about 1 day.
Secret keysRedThe payment service key is visible in the code sent to the browser.Move it server-side and rotate it.
BackupsAmberDaily backup is on, but a restore has never been tested.Test a full restore.
Account ownershipAmberThe database and the domain name are in the provider’s name.Transfer the accounts to you.
Code structureGreenReadable, organised code, a few duplicates to clean later.Keep.
Monthly costsGreen€85 a month today, about €450 at 10 times more users.Nothing to change for now.
Verdict: keep the app. 2 urgent fixes, 3 to plan, no rebuild.
- Week 1: data access and secret keys
- Weeks 2 and 3: partial features and backups
- Then: account transfer, then new features
04 / Options
Three options
The first two have a fixed price. The takeover is priced from the audit.
Express assessment
about 3 working days
excl. VAT€1,200
- Security, code, data and costs
- A green, amber or red light for each point
- 1-hour video debrief
Full audit + roadmap
about 5 working days
excl. VAT€2,400
- Everything in the express assessment
- What really works, feature by feature
- Costed roadmap: keep, fix, replace
Takeover and launch
usually 2 to 8 weeks
from · excl. VAT€5,000
- Security fixes and blocking bugs
- Production launch and error monitoring
- Documentation and handover
Read-only access, removed at the end. NDA available. I take a limited number of audits each month, depending on my current assignments.
Why this price?
The express assessment costs €1,200 excl. VAT, less than two days at my day rate. It saves you weeks of development in the wrong direction, or a rebuild you do not need.
Tight budget? Start with the express assessment: it tells you what is urgent. The full inventory and roadmap can come later.
05 / Right for you?
Is the audit right for you?
I would rather tell you before the call.
The audit is for you if
- Your app exists: live, in testing, or delivered by a team or an agency.
- You want to know what it is worth before spending more, hiring or raising money.
- You want a report you understand, even without a technical background.
- You can give read-only access to the code and the tools.
It is not for you if
- Your app does not exist yet: that is what Product development is for.
- You want someone to approve a decision already made. The report says what it sees.
- You want to rebuild everything on principle. I only recommend rebuilding what needs it.
06 / Scope
What you receive
A report written to support a decision, readable by a founder and by a developer.
Included
- An inventory of what really works, with the full audit
- A green, amber or red light for each point checked
- Examples taken from your own code
- A plan: what to keep, what to fix, what to rebuild
- Monthly costs today and at 10 times more users
- A 1-hour video debrief to decide together
Not included
- The fixes themselves: that is the takeover option, or your team using the plan
- Any change to your app during the assessment: access is read-only
What changes the price
- Express assessment or full audit: fixed price, known upfront
- Takeover: usually 2 to 8 weeks, depending on what the assessment finds
07 / How it works
From access to your code to an action plan
You keep control of your accounts throughout. I only read.
- 01
Read-only access
You invite me with read-only access to the GitHub repository and the project (Supabase, Firebase…). Access is removed at the end, and I can sign an NDA.
You receiveRead-only access, NDA if needed
- 02
Analysis
Data security, code structure, backups, account ownership and monthly costs.
You receiveEvery point checked in your code
- 03
Report
A green, amber or red light for each point, with examples from your code and a keep, fix, rebuild plan.
You receiveA rating for each point
- 04
Debrief
One hour to decide together: you carry on alone with the plan, I fix it, or I take on the technical leadership.
You receiveA decision, and next steps if you want them
08 / Selected work
My experience with apps in production
A platform with more than 150,000 registered users and an app launched in 14 days. Both run in production.
Co-founder · Technical leadership
Welco
Co-founder and CTO: microservices architecture (Node.js, gRPC, Kubernetes, MongoDB), Flutter app and tech team.
- registered users
- 150K
Personal product · Mobile app
BabyCheck
My Flutter app, designed and published on iOS and Android in 14 days, then improved with parents’ feedback.
- new users in 12 months
- 5,766
- products scanned
- 10K
- monthly recurring revenue
- $206
Engineering Manager · Oncology
Resilience Care
An 8-month engagement in oncology: two teams, health data and the requirements that come with it.
- people managed
- 10
- teams
- 2
These figures describe the size of the projects I have led.
« Jérémy est de très bon conseil. Il nous permet de comprendre des sujets techniques en les abordant de manière pédagogique. »09 / Questions
Your questions about the audit.
Another question? Ask me directly: I reply personally.
How much does the audit cost?
€1,200 excl. VAT for the express assessment (about 3 working days), €2,400 excl. VAT for the full audit with a costed roadmap (about 5 working days). Takeover and launch start at €5,000 excl. VAT.
Is the first call free?
Yes. 15 minutes on video, free and with no commitment: I tell you which option fits, or whether the audit would not help you.
My budget is limited. Where should I start?
With the express assessment. It covers security, code, data and costs, and tells you what is urgent. The full inventory and roadmap can come later.
My app handles health data.
I led two teams at Resilience Care, in oncology. I also check where this data is hosted and who can access it, and I can work without any real patient data.
What access do you need?
Read-only access to the GitHub repository and the project (Supabase, Firebase…). I do not change anything. Access is removed at the end, and I can sign an NDA.
My app is no-code, with no code to read. Can you still assess it?
Yes. I check what the tool lets you export, data security, account ownership and costs. The report says whether the app can stay on the tool or whether you need an exit plan.
What if the report says everything needs rebuilding?
It explains why, point by point, with examples from your code. You then decide: carry on alone with the plan, hire me for the fixes, or hand me the technical leadership.
Can you work with our developer or agency?
Yes. The report is written so they can use it: priorities, examples and a plan. They can join the debrief.
Is everything done remotely?
Yes: read-only access, a written report and a 1-hour video debrief. I am based in Valence, France, and work with companies remotely.
Your next step
Have your app audited before investing more
Tell me how it was built, what it should do and what worries you. In 15 minutes, I will tell you which option fits.