Alex paid¥18,400
交換 · kōkan · exchange
Shared expenses, from first payment to final repayment.
Record who paid, choose how each expense is split, and see what each person owes. When the group settles, Coukan creates a repayment plan and records each payment after the recipient confirms it.
Closed alpha. Accounts are invitation-only and public registration is disabled.
Coukan for macOS
Install the latest Mac app.
The download always points to the newest Coukan macOS release. Updates can be installed from inside the app after the first installation.
Download the latest DMG- 1Download
Open the latest Coukan DMG from this page.
- 2Install
Drag Coukan into the Applications folder.
- 3Open
Launch Coukan from Applications and sign in.
The name
The spelling is ours. The idea is exchange.
Coukan is a play on the Japanese word kōkan—交換—meaning exchange. Shared expenses are exchanges of trust as much as money: one person covers dinner, another buys the tickets, and the group works out the rest later.
Coukan keeps the expense, resulting balances, repayment plan, and recipient confirmations in one shared history. It records transfers but does not move money.
kōkan/koː.kaɴ/exchange · interchange
Available in the current alpha
What Coukan can do today
Record expenses and payments, calculate balances, and reconcile a group. Coukan does not process transfers. Access remains invitation-only while signed Apple releases and live callback checks are completed.
One record for the group
See members, expenses, payments, balances, notices, and activity without searching through a chat history.
Five ways to split an expense
Split equally, by percentage, by shares, by exact amount, or by each person’s item total. An expense can also have multiple payers.
Ten supported currencies
Record expenses in ten currencies. Each conversion keeps the reference rate—or manual rate—used for that expense.
Recipient-confirmed repayments
Create a repayment plan, let payers mark transfers as sent, and update the ledger after each recipient confirms receipt.
Search, budgets, and recaps
Search expenses, assign categories, set a group budget, review spending summaries, and archive the group with a final recap.
iPhone, macOS, and web
Use the same account, group records, and calculation rules on each supported platform.
How settlement works
From the first expense to a confirmed repayment.
- 1
Add the people involved
Include account holders and placeholders for people who have not joined.
- 2
Enter each expense
Choose the payers, participants, currency, category, and split method.
- 3
Create a repayment plan
Generate and approve the transfers needed to bring every balance to zero.
- 4
Confirm received payments
The payer marks a transfer as sent; the recipient confirms what arrived.
Privacy
Financial context, without ad tracking.
Coukan stores the account and group data needed to run the service. The public site does not use advertising or analytics trackers. Diagnostic logs stay on the device unless a tester chooses to send them.
Read the privacy policyNopayment processing
Noads or data sales
Noautomatic log uploads
Yesrecipient confirmation
Closed alpha
A smaller alpha, on purpose.
Coukan is currently available to invited adults. Accounts are approved directly. Features and stored data may change during testing, so avoid entering more financial detail than necessary.