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Sumglass
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A shared expense book in any currency

Show where the money went.

Record spends in any currency from your phone. Rates freeze on the day. The people who fund you read along, in their language.

Free to use. Sign in with an email link. No password, no card.

See what a reader sees
Laochan
Available
4,908.70USD
Received
5,254.62
Spent
345.92
This month
327.92
x

About 11 months left at the last 3 months' pace.

October 2026+2,836.24
September 2026+2,072.46

Blue is converted to USD at the rate of the day, black was entered in USD, green is money in.

The ledger as the owner sees it. Sample data.

What the book does

Numbers that stay put

Each entry keeps the rate it used, where the rate came from, and the date. Months later, it still reads the same.

Rate
1 USD = 33.7120 THBECB rate published Sat, Oct 17, 2026
Balance after
4,944.29USD
Date
Sun, Oct 18, 2026
Added by
Dara
Entry
#45
An entry opened to its rate

Rates frozen on the day

Each entry stores the ECB rate published on or before its date, and that date. A Saturday bill uses Friday's rate and says so. Saved entries are never re-priced.

Rate
1 USD = 3.6725 AEDEntered by hand on Thu, Oct 22, 2026
Balance after
4,921.15USD
Date
Thu, Oct 22, 2026
Added by
JJ
Entry
#46
A manual rate, marked as such

Any currency, one balance

Pay in baht, yen or dirhams and see every entry in your base currency with the original amount underneath. No ECB rate for your currency? Type it once. It is marked manual and filled in next time.

Rate
1 USD = 33.7290 THBECB rate published Wed, Oct 14, 2026
Balance after
4,952.00USD
Date
Wed, Oct 14, 2026
Added by
JJ
From
DraftedBooking.com confirmation 1182-5520 for Hotel Muse Bangkok, 11–14 Oct. Paid in full: THB 9,600.
Entry
#44
A drafted entry with its source

Draft from a receipt

Paste a booking email or receipt text. Sumglass drafts the entry and marks what to check. You press Save, and the source stays on the entry.

Rate
Entered in USD, no conversion.
Balance after
2,072.46USD
Date
Mon, Sep 28, 2026
Added by
Dara
Entry
#42
Entries carry who added them

Others add their own

Invite writers by email. They add entries under their name. Only you can share or archive. Mistakes are reversed, not erased, so both entries stay.

How it works

Three steps, then it runs itself

  1. Create a project

    Name it and pick a base currency. One project is one book of money.

  2. Record what comes in and goes out

    Type the amount in any currency. The base amount appears before you save.

  3. Send a view-only link

    Pick the projects and the language. Copy the link. Revoke it any time.

For the people who fund you

Nothing to install. Nothing to sign up for.

Whoever's money it is opens one link and sees what was received, what was spent, who added it, and what is left.

  • Reads in English or Japanese. Tap any title to translate it.
  • Search, filter to spends, and see each month's totals.
  • One link can cover several projects, each in its own currency. No blended totals.
  • View only. You can revoke it any time. No IP address is stored for a view.
Laochan閲覧のみ
残高あり
4,908.70USD
入金
5,254.62
支出
345.92
今月
327.92
x

直近3か月のペースなら残り約11か月です。

2026年10月+2,836.24

青はその日のレートでUSDに換算した金額、黒はUSDで入力された金額、緑は入金です。

The same book, opened from a link in Japanese

Built in the open

No testimonials yet. Here is what you can check instead.

Why this exists

Sumglass began as the book we kept for our own projects, spending deposits in yen and baht and dollars and owing the people behind them a clear account. The spreadsheet kept drifting. So each rate now freezes with its date, and the reader gets a link instead of a report.

Security and data

  • Sign in by email link. There is no password to leak.
  • Reader links are long random tokens; only a hash is stored. Revoke one and it stops working at once.
  • The balance is the sum of what was saved. Received minus spent, nothing recalculated.
  • Export or delete your account and its books by emailing privacy@sumglass.com.
Read the privacy statement

Pricing

Free to keep. Pay only for readings.

The book

Free

  • Projects in any currency
  • Writers who add their own entries
  • View-only links, revoked any time
  • Translation for readers

Readings

$0.05per reading

One reading drafts one entry from a receipt or email.

  • Your first 5 readings are free.
  • Top up any amount from $10 to $500.
  • Readings never expire. No subscription. Wrong reading? Get the credit back.

Prices in USD. Tax is shown at checkout.

Questions

Asked before you ask

Your next spend could be your first entry.

Start a book, record one spend, send one link.

No password. No card.