Costline: Budget & Expenses
Know what you spent this month, and what changed.
Costline is a budget tracker for one person or a whole household. It asks for as little as possible when you add an expense, and it explains your month instead of leaving you to read charts.
An expense in a few seconds
Tap a category, type the amount, done. The date, a note, who paid and whose it is stay behind "Add details" — useful, never required. Bills due this month wait on the home screen and take one tap to record, and "Same as last time" repeats a regular purchase.
What changed, not just charts
The first screen answers "how much this month?". Analytics goes further: this month against last month and the same month last year, 3-, 6- and 12-month averages, the categories that moved most, and a step-by-step bridge from last month's total to this one. Every chart has a table view too.
One budget for the household
Invite a partner, family or flatmates with a link, a code or a QR code. Everyone adds from their own phone or the browser, and each entry shows who added it, who paid and whose it is. If two people change the same entry while offline, nothing is lost: the other version waits in the activity log and can be put back.
Offline first
Your budget lives on your device, so Costline opens straight away — with years of entries — and keeps working without a connection. Sign in with a code sent to your email to sync between your devices and share budgets; until then nothing leaves your device.
Paid in another currency
On a trip or ordering from abroad, type what you paid in euros, pounds or yen. Costline adds its value in your budget's currency at the European Central Bank rate for that day — and you can change it to what your bank actually charged. The entry keeps both.
Cards and loans, counted once
Pay with a credit card, then pay the card bill, and Costline counts the spending once. Loans, mortgages and other financial obligations have a place of their own.
Your data stays yours
No bank connection and no reading your email. Export everything as CSV — transactions and categories — whenever you like.
On the web as well
The same app runs in your browser at costline.appsbybaa.com: at a desk, on a laptop, or before the iPhone version reaches the App Store.
What it does
- Add an expense with a category and an amount; everything else is optional
- Bills due this month on the home screen, recorded with one tap
- Month-to-month and year-to-year comparison, 3/6/12-month averages
- A bridge chart that shows which categories changed your total
- Shared household budgets by link, code or QR code
- Added by, paid by and whose it is on every shared entry
- Offline entry that syncs when you are back online
- Expenses paid in another currency, at the day's ECB rate
- Credit card payments and card bills counted once
- Search and filter by text, date, category, person and amount
- CSV export of transactions and categories
- English and Turkish
Questions
- Is there a web version of Costline?
- Yes. The full app runs in the browser at costline.appsbybaa.com, with the same budgets, charts and sharing as the phone app. Sign in with the same email on both to keep them in sync.
- Does Costline connect to my bank?
- No. Costline never asks for bank access or reads your email. You add expenses yourself, which takes a category and an amount.
- Can I use it without an account?
- Yes. Everything works on one device without signing in. An account — a code sent to your email, no password — is only needed to sync between devices or share a budget.
- Can my partner and I share one budget?
- Yes. Create a household budget and invite them with a link, a code or a QR code. Both of you add expenses from your own phones and see the same totals; each entry shows who paid and whose it is.
- Where is my data stored?
- On your device first. If you sign in, a copy is kept on our sync server in the EU (Frankfurt) so your other devices and the people you share a budget with can see it.
- When is Costline coming to the App Store?
- The iPhone and iPad app is in testing now. Until it is out, the web version at costline.appsbybaa.com is the same app.