| Criterion | Take over | Refactor | Rewrite |
|---|---|---|---|
| Code condition | Readable, structured, partly tested | Sound foundations, fragile areas identified | Unreadable, unstructured, or missing |
| Dependencies | Up to date or easy to upgrade | A few heavy version upgrades | Abandoned or outdated frameworks |
| Effect of a fix | Contained | Side effects in some areas | Every fix breaks something else |
| What you keep | All the code | The structure, the data, much of the code | The data, the business rules, the validated screens |
| Timeline | Right after the audit | In batches, alongside new features | 4 to 8 weeks of development, like an MVP |
| Price range | Time and materials, €700 to €1,100 excl. VAT per day, or time credit | Time and materials or time credit, quoted batch by batch | MVP pricing: €6,000 to €25,000 excl. VAT for mobile, €6,000 to €30,000 excl. VAT for SaaS |
| The right call when | The app runs and mostly needs to evolve | The product works, but every change costs too much | The code blocks the product, or it’s gone |
App audit and takeover.
Vanished contractor, departed CTO, an app stuck in store review or a prototype generated by AI: Krafter audits your mobile app or SaaS, secures your access and takes over the code. A written report and a costed recommendation in 1 to 3 days.
Secure. Audit. Decide. Ship.
Straight answer
Can your app be rescued?
Yes, as soon as you get the source code and the access back. A mobile app or SaaS built elsewhere can be taken over when the repository, the database and the store and cloud accounts are in your hands. The takeover audit checks this in 1 to 3 days, for €700 to €3,300 excl. VAT, and settles it: take over, refactor or rewrite. If the code can’t be found, the app is rebuilt from what still runs: screens, data, business rules.
- For whom
- Business owners and founders whose mobile app, SaaS or web tool has lost its developer.
- Audit
- 1 to 3 days, €700 to €3,300 excl. VAT.
- Deliverable
- Written report, costed recommendation, video debrief.
- Takeover
- Time and materials, €700 to €1,100 excl. VAT per day, or time credit.
- Rewrite
- MVP pricing: €6,000 to €25,000 excl. VAT for mobile, €6,000 to €30,000 excl. VAT for SaaS.
- Stacks
- Flutter, Vue.js, Python, PostgreSQL.
The situations
Four situations, one urgency: take back control.
An app that loses its developer doesn’t stop overnight: it degrades, then breaks at the worst moment. Each situation has its signals and its next steps. Depending on the case, what follows is mobile development, SaaS development or application maintenance.
Orphaned software or SaaS
The contractor vanished, the agency closed, the freelancer stopped answering.
The signals
Requests go unanswered. Nobody knows how to deploy a fix. Hosting is billed to a name you don’t recognize.
What to do
Secure access within 72 hours, recover the repository and the database, then get an audit before signing with anyone.
Unfinished app, publication blocked
The app has been “almost done” for months, or the stores keep rejecting it.
The signals
Apple review rejects every submission. The developer account is in the contractor’s name. The SDKs are too old for the latest iOS and Android versions.
What to do
List what’s left, check the store accounts, fix the rejection reasons, update the dependencies, then publish.
Developer or CTO gone
One person knew the code, and they’re leaving.
The signals
No documentation. Passwords live on their laptop. Releases were done by hand, by them alone.
What to do
Get admin access back before they leave, have the deployment documented, then audit while they can still answer.
AI-generated app
A prototype built with Lovable, Bolt or Cursor that now has to welcome real customers.
The signals
Nobody knows what the code contains. API keys sit in the browser code. Customer data isn’t isolated. Every fix breaks something else.
What to do
Keep the validated business logic, audit security and data, rebuild what won’t hold in production.
Urgent
The first 72 hours: secure before you decide.
Before choosing who takes over, put what could disappear somewhere safe. These six moves require no technical skills, and they keep every option open: take over, refactor or rewrite.
Open access to the code repository
Get admin access to the Git repository (GitHub, GitLab, Bitbucket), or failing that a full archive with its history. Add a second trusted admin.
Take back store and cloud accounts
Check whose name the Apple Developer account, the Google Play console, the hosting and the cloud services are in. Change passwords, turn on two-factor authentication.
Lock down the domain and DNS
Identify the registrar, the expiry date and who has access. An expired domain takes down the site, the app and email at once.
Back up the database
Export the database and files, store the copy outside the current hosting, check that it restores. A backup never restored is only a hope.
Inventory secrets and API keys
Payments, email, notifications, maps: list every key and who can reach it. Rotate them once you know where they’re used: a key changed blindly can take the app down.
Request the code in writing
Send a dated request for the source code, access and documentation. If the contractor refuses, the legal side belongs to a lawyer: this written record will help them.
The takeover audit
Eight checks, in 1 to 3 days.
The takeover audit puts your app through eight checks, for €700 to €3,300 excl. VAT. AI speeds up reading the code. Every finding is then checked by a senior partner before it goes into the report.
Code
Readability, structure, tests, conventions. Can another developer evolve it without breaking everything?
Architecture
Structure, technical choices, ability to scale, single points of failure.
Dependencies
Framework versions, Flutter or native SDK, abandoned libraries, known vulnerabilities.
Security
Authentication, role-based access, exposed secrets, encrypted traffic, common flaws.
Data and isolation
Data model, backups, customer isolation in a SaaS, GDPR compliance.
Store accounts
Who holds the Apple and Google accounts, certificates, rejection history, review rules.
Access
Who holds what, from the repository to the domain, and what is still missing.
Technical debt
What it already costs on every change, and what to pay back first.
Budget
How much does a code audit before a takeover cost?
A takeover audit takes 1 to 3 days, or €700 to €3,300 excl. VAT depending on the size of the app: a mobile app alone, a SaaS with a back office, or both connected by an API. You get a written report, a costed recommendation and a video debrief with the partner who read your code. The report is yours: it stays useful whatever comes next.
- Duration
- 1 to 3 days of work.
- Price
- €700 to €3,300 excl. VAT.
- Deliverable
- Written report and costed recommendation: take over, refactor or rewrite.
- Debrief
- By video, with the partner who read your code.
- Method
- AI-assisted analysis, every finding checked by a senior partner.
- After the audit
- Time and materials, €700 to €1,100 excl. VAT per day, or time credit.
Decision
Take over, refactor or rewrite?
Take over when the code is sound, refactor when the foundations hold, rewrite when every fix breaks something else. The audit decides with costed findings, not with a preference.
Missing code doesn’t stop you. The app is rebuilt from what still runs: screens, flows, data and business rules. For a rewrite, the budget simulator gives your range in 8 questions.
Reversibility
Who holds what? The reversibility checklist.
Your app is truly yours when these eight items are in your name. Check them now, not the day the contractor stops answering.
| Item | What you should hold | The common trap |
|---|---|---|
| Git repository | An organization in your name, with you as admin | The repository on the developer’s personal account |
| Apple and Google accounts | The Apple Developer account and Google Play console in the company’s name | The app published under the contractor’s account: no updates without a transfer |
| Cloud and hosting | The account and billing in your name | A server paid by the contractor, then re-invoiced |
| Database | Admin access and a full export | Data only reachable through the app |
| Domain | The domain name in your name, access to the registrar | A domain in the agency’s name, renewal forgotten |
| API keys | Third-party service accounts (payments, email, notifications) in your name | Keys created on the developer’s personal accounts |
| Backups | Automated, stored off the server, restored at least once | A backup on the same server as production, never tested |
| Documentation | Installation, deployment, architecture, list of accounts | Everything lives in one person’s head |
The Krafter rule: at the end of a project, everything is put in the client’s name. Git repository, store accounts, cloud, access. Only the open source stack stays under its own license.
Legal ownership of code written by a former contractor depends on your contract and its IP assignment clause: a question for your lawyer.
Method
Secure, audit, decide, take over, maintain.
A successful takeover always follows the same order. Skip a step and you pay later for what nobody saw.
01 / 05
Secure
72 hoursAccess, accounts, domain, backups: everything that could disappear is put somewhere safe.
Before anyone reads a single line of code, the six moves of the first 72 hours keep every option open.
Audit
1 to 3 daysCode, architecture, dependencies, security, data, store accounts, access, technical debt.
AI speeds up reading the code. Every finding is checked by a senior partner before it goes into the report.
Decide
video debriefTake over, refactor or rewrite: a costed recommendation, and you decide.
The written report is yours. If an option isn’t worth its price, it says so in black and white.
Take over
time and materials or time creditUrgent fixes, updates, a blocked release unblocked, then new features.
Every version is reviewed and tested by a senior partner before going to production or to the stores.
Maintain
over timeUpkeep at 8 to 12% of development cost per year, new features at the pace of your roadmap.
Everything stays in your name. If you build an internal team, it takes over reviewed, documented code.
Why Krafter
Two seniors who run their own products in production.
Taking over someone else’s code means knowing what breaks in production. Krafter lives it on its own products. Melimelo, our Flutter home organization app, has over 50 versions published on the App Store and Google Play, none rejected by Apple or Google. Trottr, our field service management SaaS, is used by companies including Engie.
Our stacks are the ones we run every day: Flutter for mobile, Vue.js for the web, Python and PostgreSQL on the server, Docker for deployment. Flutter has been in production at Krafter since 2024. If your app relies on a technology too far from ours, we say so in the first conversation rather than learning on your invoice.
No subcontracting, no sales layer. Fabien Maquin, CEO, and François Pluchino, CTO, read your code, write the audit and take over the app themselves. AI writes a large share of the code; every line is reviewed and tested by one of them. The studio was founded in 2021 in Morancé, near Lyon, France, and works with clients by video.
Melimelo is freely available on the App Store and on Google Play. Read the Melimelo case study.
After the audit
What we take over.
iOS and Android mobile app
#1An app built elsewhere, to fix, update or finally publish. Store accounts back in your name, versions kept up with every iOS and Android update.
ExploreFlutter app
#2Our production mobile stack since 2024. SDK upgrades, dependencies, fixes and new features, on a single codebase.
ExploreSaaS and web platform
#3An orphaned SaaS or one born from an AI prototype: security, customer isolation, subscriptions, then the roadmap.
ExploreMaintenance after takeover
#4Upkeep at 8 to 12% of development cost per year, new features on time and materials or time credit.
ExploreFAQ
Vanished contractor, blocked release, AI prototype: describe the situation, and a partner tells you where to start.
Discuss my projectBefore taking over your app.
A takeover audit takes 1 to 3 days, or €700 to €3,300 excl. VAT depending on the size of the app: a mobile app alone, a SaaS with a back office, or both connected by an API. It includes a written report, a costed recommendation (take over, refactor or rewrite) and a video debrief with a senior partner.
Eight things: code quality, architecture, dependencies, security, data and customer isolation, store accounts, access and technical debt. AI speeds up reading the code, then a senior partner checks every finding before it goes into the report. The whole audit fits in 1 to 3 days.
Secure what could disappear before looking for a replacement. In the first 72 hours: access to the code repository, store and cloud accounts, domain and DNS, a full database backup, an inventory of API keys, and a written request for the code. Only then does a 1 to 3 day audit tell you whether the app can be taken over.
The legal side belongs to a lawyer: your contract, the IP assignment clause and any formal notice are their ground. Krafter handles the technical side: an inventory of what you already hold, recovery of what is still reachable (database, accounts, published app) and a plan to move forward, with or without the old code.
Yes, by rebuilding it. What still runs is a valuable base: screens, flows, data, observable business rules. The audit inventories what exists, the database is recovered when possible, then the app is rewritten on MVP pricing: €6,000 to €25,000 excl. VAT for mobile, €6,000 to €30,000 excl. VAT for SaaS.
With Flutter, the takeover is direct: it has been our production mobile stack since 2024. With native code (Swift, Kotlin) or React Native, the audit tells you whether to maintain what exists or move to Flutter for a single iOS and Android codebase. If the technology is too far from ours, we say so in the first conversation.
Rarely as is. An AI-generated prototype proves the product deserves to exist, but security, data isolation and tests are often missing. The audit sorts what to keep, starting with the business logic validated by real use, from what to rebuild. The takeover is then scoped like an MVP, between €6,000 and €30,000 excl. VAT.
Open your own developer accounts ($99 per year at Apple, $25 one-time at Google), then request a transfer of the app. Apple and Google both provide a transfer between developer accounts, which requires the current holder’s consent. As long as the app stays under their account, you can’t publish any update without them.
Yes. We read the rejection reasons, fix the app and its listing, update outdated dependencies, then resubmit. We practice review rules on our own apps: Melimelo has over 50 versions published, none rejected by Apple or Google, with Apple review usually taking 1 to 2 days.
Not necessarily. If the foundations hold, refactoring in batches costs less and keeps the app online during the work. A rewrite makes sense when every fix breaks something else, when the frameworks are abandoned or when the code is missing. The audit compares the cost, timeline and risk of each option.
It depends on the recommendation. A takeover or refactoring is billed on time and materials, €700 to €1,100 excl. VAT per day, or as prepaid time credit. A rewrite follows MVP pricing: €6,000 to €25,000 excl. VAT for mobile, €6,000 to €30,000 excl. VAT for SaaS. Upkeep then runs at 8 to 12% of development cost per year.
Organize the handover before they leave. Get admin access to the repository, cloud, stores and domain, have the deployment and the list of accounts documented, back up the database. A takeover audit during their notice period lets you ask questions while they can still answer, in 1 to 3 days.
You do. Code written during the takeover is yours, and at the end of the project everything is put in your name: Git repository, store accounts, cloud and access. Only the open source stack stays under its own license. For code written by the former contractor, ownership depends on your contract and its IP assignment clause.
Let’s build a product people → actually use
A 30-minute call with a founder. Answer within 24/48h. Pitch deck optional.