--- title: "€co-Survivor: Offline Budget App for Android — Survival Apps" description: "How €co-Survivor is built: an offline React Native + Expo budget app with a post-apocalyptic theme — reserves, rations, a survival index." url: https://survival-apps.com/en/transmissions/014-ecosurvivor-managing-finances-like-a-survivor/ --- TRANSMISSION 014 · 18 JUL 2026 ARCHIVE: [ZONE 2 — MOBILE / ANDROID](https://survival-apps.com/en/zone-2/) · CASE STUDY # €co-Survivor: Managing Your Finances Like a Survivor (React Native + Expo) The Weaver — build log ![Two phones running the €co-Survivor app next to the shield emblem with a dollar sign: on screen, the Bunker dashboard with total reserves and the yearly chart, and the ration plan; beside them the €CO-SURVIVOR title and the words React Native + Expo](https://survival-apps.com/assets/img/ecosurvivor-hero.webp) Fig. 1 — €co-Survivor: the “Bunker” dashboard and the ration plan. Zone 2, an app that runs entirely on your phone. A crisis never arrives all at once: it builds up one line of the balance sheet at a time, usually while you're looking the other way. This is an app for people who decided to look. They call it a finance manager; in its own language, every euro you don't spend is one more ration to get you through the winter. ## What €co-Survivor is **€co-Survivor** is an Android app for managing personal finances, dressed up as a survival manual. The idea is simple: treat your budget like the supplies in a bunker. Income and expenses become *reserves*, category budgets become *rations*, and a *survival index* tells you, with a single number, how long you'd last at your current pace. Alongside it there's a *field manual*: ten chapters of economics education — inflation, the emergency fund, the 50/30/20 rule, compound interest — written in the same tactical language. The framing is theatrical, but the craft underneath is concrete: an offline budget tracker, with no account, no cloud, no ads. Everything you write stays on your phone. It's a **Zone 2** project in its most direct form: a mobile app, from concept to build, shown as it's made on the inside. ## How it's built €co-Survivor is a **React Native** app built with **Expo**[[1]](https://survival-apps.com/en/transmissions/014-ecosurvivor-managing-finances-like-a-survivor/#nota1): not native Kotlin, and not a Capacitor wrapper. [That choice](https://survival-apps.com/en/transmissions/007-pwa-capacitor-or-native/) pays off in development speed and in a single TypeScript codebase that describes every screen. - **REACT NATIVE + EXPO** — React Native 0.81 on Expo 54 (managed workflow), with the *New Architecture* enabled and the React Compiler. Navigation is **expo-router**[[2]](https://survival-apps.com/en/transmissions/014-ecosurvivor-managing-finances-like-a-survivor/#nota2): routes come from files, and the four tabs at the bottom are a tab navigator. - **DATA ON THE DEVICE** — no remote database, no network calls. Everything is saved locally with **AsyncStorage**[[3]](https://survival-apps.com/en/transmissions/014-ecosurvivor-managing-finances-like-a-survivor/#nota3), the phone's key-value store, under three keys: transactions, budgets and language. Close the app, reopen it, and the data is still there — without ever having passed through a server. - **OFFLINE BY DESIGN** — it doesn't “work offline too”: it's *only* offline. There's no login, no sync, no artificial intelligence crunching your transactions in the cloud. Privacy here rests on a fact: there is no one the data could reach. - **TWO CONTEXTS, ONE BRAIN** — state lives in two React *contexts*: one for finances (transactions, budgets, totals and the survival index) and one for language (Italian/English, with a translator that feeds every label). Everything else is components reading from here. - **HAND-DRAWN IN SVG** — the yearly chart, the index bar, the hazard-tape badges and the textures are **react-native-svg**, not images. *Inter* font, Feather icons, a touch of *haptics* when you log an entry. There's only one aesthetic: rusted metal, toxic gold, blood red. Zone note Zone 2, but with a Zone 1 rule underneath: a tool that has to outlive third-party services. There aren't any here — no backend, no account, no subscription that expires. The app lives and dies with the phone it runs on. ## The survival index The number that holds everything together is the **survival index**, from 0 to 100. It isn't an arbitrary grade: it starts from the *savings rate* — how much of your income is left after expenses. Breaking even is worth about 40; saving half of what comes in pushes you toward 80; spending more than you earn drags the number toward zero. On top of that base works the **ration discipline**: if you respect your category budgets the index gains a few points, if you blow through them it drops. Anyone spending with no income goes straight into *critical condition*. On screen the number doesn't just appear: the bar fills with an animation lasting a little over a second, and the label changes color — from “optimal survival” in green down to “critical condition” in red. It's honest gamification: it doesn't promise you wealth, it tells you how well you're holding up. ![€co-Survivor Bunker screen: €CO-SURVIVOR header, Total reserves card showing €1,240.00 with income in green and expenses in red, Survival index card at 68 percent with a bar and the status Stable conditions, yearly bar chart of income/expenses with a balance line, Latest operations list and an Add button](https://survival-apps.com/assets/img/ecosurvivor-bunker.webp) Fig. 2 — the “Bunker”: reserves, survival index, yearly trend and latest operations at a glance. ## The four screens The app is a bar of four tabs, each with a barracks-style name: - **BUNKER** — the dashboard. At the top the *total reserves* (the balance, which turns red if you go under), below it the survival index, then a chart of the last twelve months with income, expenses and the net balance line, and finally the latest operations. The **ADD** button starts here. - **LOG** (Supply Log) — the journal of all operations, filterable by *all / income / expenses*. Each entry has its category, date and signed amount; a long press deletes it, with confirmation. - **RATIONS** (Ration Plan) — monthly budgets by category. You set a limit and the bar fills as you spend: green while you're on track, orange as you get close, red with a “ration exceeded” when you blow through it. - **MANUAL** (Field Manual) — the ten chapters of tactical economics, sorted by difficulty (beginner, advanced, expert). Each one opens in a pop-up card with the full lesson. ![€co-Survivor Supply Log screen with the All/Income/Expenses filters and the transaction list, overlaid by the New log entry modal: Expense/Income selector, category chips, Amount field showing 48.50 euros, Notes field and the Log it in the bunker button](https://survival-apps.com/assets/img/ecosurvivor-registro-add.webp) Fig. 3 — the log and the “New entry” modal: type, category, amount, note, and you're logged. ![€co-Survivor Ration Plan screen: Total monthly budget card showing €820 of €1,150 at 71 percent, and the list of rations by category with progress bars — Food and Rations at 92 percent, Fuel with ration exceeded +€40 in red, Shelter, Transport still to be set, and Medical](https://survival-apps.com/assets/img/ecosurvivor-razioni.webp) Fig. 4 — the rations: a spending ceiling for each category, with an alert when you go over. ![€co-Survivor Field Manual screen: header Knowledge is survival, 10 chapters of tactical economics on cards with difficulty badges — Inflation, The Emergency Fund, The 50/30/20 Rule, Debt, The Power of Compounding, Crypto and Alternative Assets](https://survival-apps.com/assets/img/ecosurvivor-manuale.webp) Fig. 5 — the field manual: ten economics lessons, from the simplest to the most demanding. ## How to use it The flow, from the first launch onward, is short by design: - **1 · THE INITIAL PACT** — on first launch the app shows a *disclaimer*: €co-Survivor is an educational tool, not financial advice. You scroll through it, tick “I have read and accept” and carry on. The language starts in Italian, with an IT/EN switch always within reach. - **2 · LOGGING AN ENTRY** — the red **ADD** button opens the modal: pick *expense* or *income*, tap the category (food, shelter, transport, fuel… or work, trade, investment), type in the amount and a note, and hit **“Log it in the bunker”**. Totals, chart and index update instantly. - **3 · SETTING THE RATIONS** — in the Rations tab you tap a category and set the monthly limit. From then on the bar tells you at a glance how much room you have left before the alert. - **4 · KEEPING THE LOG** — in the Log you filter entries and, with a long press, delete the wrong ones. No entry is carved in stone. - **5 · STUDYING** — when you have a minute, open a chapter of the Manual. They're short lessons, meant to be read on your phone. - **6 · STARTING OVER FROM ZERO** — from the settings, “reset everything” wipes transactions and budgets after a confirmation. Handy for closing out a period or starting clean. root@survival:~$ arch --project ecosurvivor > ui: react native + expo (expo-router) · typescript > storage: asyncstorage (device) · transactions · budgets · lang > network: none · offline-only · no account · no cloud · no ai > graphics: react-native-svg · inter font · feather icons > core: survival-score 0–100 = savings ± ration discipline ## Frequently asked questions ### What technology is €co-Survivor built with? It's a **React Native** app built with **Expo** (managed workflow, expo-router for navigation), written in TypeScript. It isn't native Kotlin, nor a web app packaged with Capacitor: it's a single codebase that generates the Android app. ### Where does my data go? It stays on your phone. Transactions, budgets and the language preference are saved locally with **AsyncStorage**. There's no server, no account and no cloud sync: your data never leaves the device. ### Does it work without a connection? Yes, always. €co-Survivor is offline by design: it makes no network calls to work. You can use it in airplane mode from start to finish. ### Is there any artificial intelligence or advertising? No. No AI analyzing your spending, no ads, no tracking. The survival index is a deterministic calculation that runs on the phone, not a remote model. In the end it's just arithmetic — but read carefully, it tells you where you are and how far you have left to go. May your reserves outlast the winter, and your index stay green even when it's raining ash outside. ### Notes 1. **Expo** — a platform on top of React Native that provides tooling, ready-made libraries and a build flow without having to configure Android Studio and Xcode by hand. The “managed workflow” hides most of the native complexity. [↑ back to text](https://survival-apps.com/en/transmissions/014-ecosurvivor-managing-finances-like-a-survivor/#ref1) 2. **expo-router** — Expo's file-based navigation system: the folder structure defines the screens and their paths, the way the pages of a website work. [↑ back to text](https://survival-apps.com/en/transmissions/014-ecosurvivor-managing-finances-like-a-survivor/#ref2) 3. **AsyncStorage** — React Native's persistent key-value store: it saves small amounts of data on the device, asynchronously, without a real database. Ideal for settings and local lists. [↑ back to text](https://survival-apps.com/en/transmissions/014-ecosurvivor-managing-finances-like-a-survivor/#ref3) root@survival:~$ buy --app ecosurvivor 7.99 € VAT included · one-time payment, no subscription Pay by card — no account needed · or with PayPal [Buy EcoSurvivor](https://payhip.com/b/Cvqf8) [Full details](https://survival-apps.com/en/ecosurvivor/) ## // FROM THE SAME ZONE [ TRANSMISSION 038 20 OCT 2026 ZONE 2 — MOBILE / ANDROID · APP PRESENTATION ### Item90: home supplies, room by room Do you know what's in your pantry, how long it lasts and what's about to expire? Item90 is the Android app for planning home supplies, in '90s pixel style. ](https://survival-apps.com/en/transmissions/038-item90-home-supplies/) [ TRANSMISSION 037 18 OCT 2026 ZONE 2 — MOBILE / ANDROID · DECISION GUIDE ### Offline maps: download them before the network is gone Google Maps, Organic Maps or OsmAnd? What really works without internet, what doesn't, and how to prepare your phone in ten minutes, before you need it. ](https://survival-apps.com/en/transmissions/037-offline-maps-android/) [ TRANSMISSION 034 29 SEP 2026 ZONE 2 — MOBILE / ANDROID · DECISION GUIDE ### Your phone already knows how to call for help: turn these features on Emergency SOS and emergency contacts are already built into Android and iPhone. Here's how to switch them on. ](https://survival-apps.com/en/transmissions/034-emergency-sos-already-in-your-phone/)