How does the app know what I own when offline?

It keeps a read-only copy of your collection on the phone: titles, barcodes, ISBNs and covers. The scan checks the code against that copy, without sending anything.

What about a weak signal?

If the server doesn't answer while the phone thinks it's connected, the app falls back to the local copy rather than lose the scan.

What happens with an item I don't own?

Its code is saved. Back online, “Look up queued scans” finds the edition, and you add it to your collection or set it aside.

Does my data stay on the phone?

The copy only holds your own collection, never another account's, and is never sent back to the server. It's erased when you sign out.

What I Already Own

Scan at the flea market, even with no signal

With no signal, What I Already Own still knows whether a record or a book is in your collection: a copy of your list is kept on your phone, and the scan checks the barcode against it. Codes for items you don't own are saved, then looked up with one tap once you're back online.

Updated September 30, 2026

Try it free

Scanning is free. At your first add: 7-day trial at €0, card required, then €3.95 a month or €39.95 a year, records and books included, cancel anytime. Your collection stays exportable.

The problem

Flea market halls, record store basements and country car boot sales have one thing in common: no signal, or a bar that loads nothing. That's exactly where you hesitate over a record. An app that asks a server at every scan goes silent right when you need it.

How the app handles it

1Install the app and open it once onlineEach time it opens with a connection, the app refreshes the copy of your collection on the phone and keeps the scan screen ready to work offline.
2Scan with no signalIf the barcode matches an item in your collection, the app shows it at once, with the date you added it.
3Other codes waitA code that isn't in your collection is saved on the phone, up to 200 scans. Scanning the same item again doesn't save it twice.
4Pick up once you're back online“Look up queued scans” finds each edition; you add each one with a tap, or set it aside.

A real app on your phone

iPhone and Android, no app store needed. Your collection stays with you, even offline.

At a glance

Offline: Tells you whether an item is already in your collection.
Queued scans: Up to 200, looked up once you're back online.
Back online: Nothing is added without your say-so.
On the phone: Your own collection only: titles, identifiers, covers. Erased when you sign out.
Devices: iPhone and Android, preferably with the app installed.

What the app doesn't do

With no signal, it can't identify a record you don't own: the catalog isn't copied to the phone, only your collection.
You need to have opened the app online on that phone: that's when your collection is copied to it.
Queued scans aren't added on their own once you're back online: you confirm each one.

Try it free

Scanning is free. At your first add: 7-day trial at €0, card required, then €3.95 a month or €39.95 a year, records and books included, cancel anytime. Your collection stays exportable.

Frequently asked questions

How does the app know what I own when offline?: It keeps a read-only copy of your collection on the phone: titles, barcodes, ISBNs and covers. The scan checks the code against that copy, without sending anything.
What about a weak signal?: If the server doesn't answer while the phone thinks it's connected, the app falls back to the local copy rather than lose the scan.
What happens with an item I don't own?: Its code is saved. Back online, “Look up queued scans” finds the edition, and you add it to your collection or set it aside.
Does my data stay on the phone?: The copy only holds your own collection, never another account's, and is never sent back to the server. It's erased when you sign out.