Knife Collection Log: Tangmark

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About this app

Private knife and EDC collection log with a carry log, maintenance history and a 115-steel reference. Catalogue the knives, flashlights and multitools you already own, plus anything else you carry: a pen, a watch, a sharpener.

Free for your first 15 pieces. Pro is one payment, unlimited, no subscription. Tangmark is a record, not a marketplace and not a price guide. Nothing is listed for sale, nothing is valued for you, and nothing leaves your device.

THE RECORD
Every piece gets a permanent inventory number that is never reused. Maker, model, variant, steel, grind, lock, blade length, weight, country and year. What you paid, in the currency you actually paid, with the exchange rate you actually got. Where it lives, down to the drawer. Its serial. Limited-edition numbering, previous owners, and who you bought it from.

Knives, flashlights and multitools each get their own field set. Anything else is a record with the fields you define yourself.

SIX FIELDS, TWENTY SECONDS
Quick add takes a photo and five facts and gets out of your way. Everything else can be filled in later, or never. Duplicate a knife you own two of: the identification and specs are copied, and you fill in the new serial. Makers and steels you have typed before are offered back to you.

CARRY LOG
Log what you carried today, save loadouts for work and for the weekend, and look back over the last two weeks. A day you did not log is simply a day with no record. A home-screen widget on iPhone and Android shows today's carry, never a value or a location.

MAINTENANCE LOG
A log of what you actually did: sharpened, stropped, oiled, taken apart, serviced. It keeps the angle per side, the grits in the order you worked them and the compound you finished on. There are no predictive due dates anywhere in this app. Reminders run on your rule, off until you set one; the reminder that actually goes off is part of Pro.

MODIFICATIONS
A ledger of what went on, what came off and what it cost, with the stock parts you kept tracked separately, so what you have spent and what you are holding never double-count.

STEEL REFERENCE
One hundred and fifteen steels with their composition, working hardness and four properties, built from maker datasheets and published tests, with the evidence behind every band shown. Every property is a range, never a verdict and never a score. The notes read in English, German, Spanish, French, Italian and Japanese. Compare two steels side by side and neither one wins. If you have tested a knife's hardness yourself, your number is the one that shows.

DOCUMENTS AND EXPORT
A Collection Inventory Schedule as a PDF, with a second copy for sharing that carries no serials and no storage locations. CSV export. A versioned backup archive with every photo. Import a spreadsheet you already keep, with the whole file mapped and previewed before a single row is written; free up to the piece limit.

PRIVATE BY CONSTRUCTION
No account. No server. No analytics on what you own. A PIN lock, with your face or fingerprint on top, is free. Pro adds the privacy pack: serials masked on screen, a private-fields switch that hides values and locations from a shoulder, and a shield that covers the collection in the app switcher.

PAY ONCE
One payment unlocks it. There is no subscription and there will not be one. Free covers fifteen pieces of any kind, sold ones included, and three photos each. Pro lifts both limits and adds document attachments, reminders that go off, two steels side by side and the privacy pack. Backup, restore, CSV export, the schedule PDF and your carry history are free at every tier and always will be.

NOT A MARKETPLACE
Nothing is listed for sale, there is no buyer contact and no price tracking. Tangmark catalogues what is already yours.
Knife collector's log: EDC inventory, carry log, steels, maintenance. Pay once.
Updated on
Sep 9, 2026

Data safety

Safety starts with understanding how developers collect and share your data. Data privacy and security practices may vary based on your use, region, and age. The developer provided this information and may update it over time.
  • No data shared with third parties
    Learn more about how developers declare sharing
  • This app may collect these data types
    Financial info, App info and performance, and Device or other IDs
  • Data is encrypted in transit
  • Data can’t be deleted

What’s new

First release.