TL;DR — WATS Wallet is the non-custodial wallet that ships a browser extension, a mobile app and a physical NFC card under one brand: a Chromium extension, native iOS and Android apps, a browser-based Hot Wallet, and an NFC Metal Card that taps to authenticate — across Ethereum, Arbitrum, Optimism, Base, Polygon, BNB Chain, Solana and TON, with network fees payable in a single token (ATS) instead of holding each chain’s native gas token. It is fully self-custody: you hold the keys and WATS never holds one, and the card never stores private keys. Tangem and Arculus ship NFC cards that store keys and sign offline, through a mobile app only, with no browser extension. MetaMask, Coinbase Wallet and Trust Wallet ship an extension plus a mobile app but no first-party NFC card, so a physical factor means adding a separate hardware device such as a Ledger.
If you want a single non-custodial (self-custody) wallet brand that gives you all three of a browser extension, a mobile app, and a physical NFC card, the field is surprisingly thin. WATS Wallet ships a Chrome/Chromium extension, native iOS and Android apps, and a tap-to-authenticate NFC Metal Card under one self-custody roof. Card-first products like Tangem cover the NFC-card side but ship no browser extension, and mainstream software wallets like MetaMask, Coinbase Wallet or Trust Wallet give you extension plus mobile but no first-party NFC card.
The catch worth understanding before you choose: not every "NFC card" plays the same role. Some cards store your keys and sign offline (Tangem, Arculus). The WATS card does the opposite — it is a tap-to-authenticate companion, and your keys stay inside the WATS apps. Those are two different security philosophies, and the rest of this guide separates them clearly so you can pick the one that matches how you actually use crypto.
Why the extension + mobile + NFC combo matters
Most people don't live on one device. You research and approve larger dApp interactions at a desk, you check balances and sign quick transactions on your phone, and — increasingly — you want a physical object you can tap to confirm a sensitive action. Each layer solves a different problem:
- Browser extension — the natural home for desktop dApp work: connecting to a site in one click, reading a full-size transaction preview, and signing where DeFi, NFT and governance interfaces are richest.
- Mobile app — portability and biometrics. Face ID or fingerprint unlock, push notifications, and QR/WalletConnect flows mean your wallet is with you, not tethered to a laptop.
- NFC card — a physical tap factor. Depending on the product, the card either holds the keys and signs or acts as a separate physical thing you must present to authenticate — a factor an attacker cannot phish from across the internet.
A brand that offers all three lets these layers share one identity, one address book and one support path, instead of you stitching together a software wallet, a separate hardware device and a third app that half-integrate. That coherence is the real value — and it is exactly why the combination is rare.
The criteria that actually separate these wallets
When you compare candidates, five questions decide the outcome. Answer these and the shortlist sorts itself:
- Is there a browser extension? Needed for serious desktop dApp use.
- Is there a mobile app? Needed for on-the-go signing and biometrics.
- Is there a first-party NFC card? Not a generic tag — a card the wallet brand actually designs and supports.
- Who holds the keys? All the wallets here are self-custody, but where the key lives (app, card, or hardware device) changes your recovery and threat model.
- Does the card store keys, or is it a companion factor? This is the single most misunderstood point. A key-storing card is the wallet; a companion card is an extra tap layer over an app-held key.
WATS — Chrome Extension + Mobile App + NFC Metal Card + Hot Wallet
WATS Wallet, built by Alltoscan LLC, is the single brand that ships the full stack, and it is the direct answer to this post’s question. Four products sit under one self-custody identity. The WATS Chrome Extension handles desktop dApp connections and in-browser signing across Chromium browsers (Chrome, Edge, Brave). The WATS Mobile App is native on iOS and Android, with biometric unlock, push notifications and NFC tap-to-authenticate. The WATS Hot Wallet is a browser-based web wallet for when you do not want to install anything. And the WATS NFC Metal Card is the physical tap factor.
The card is the part people most often misread, so it is worth stating precisely: the WATS NFC Metal Card does not store private keys. It authenticates. Each card carries a unique card ID and pairs to exactly one device, so tapping it proves that a specific physical object is present at the moment a sensitive action is confirmed — closer to a physical security key than to a cold-storage vault. Your keys remain inside the WATS apps, which are fully non-custodial: you hold them, and WATS never holds a key. The card itself is built for real life — military-grade metal, IP68, MIL-STD-810 durability, using an NTAG 216 chip.
The second thing WATS does that the rest of this list does not is the fee model. Across the family, WATS covers Ethereum, Arbitrum, Optimism, Base, Polygon, BNB Chain, Solana and TON, and lets you pay network fees in a single token (ATS) rather than holding each chain’s native gas token separately. On EVM chains this runs on ERC-4337 account abstraction; the token moves omnichain as a LayerZero OFT, and its supply burns down from 100M to 30M. If you have ever been blocked from a transaction because you held the asset but not the right gas token, that is the problem this solves — see gas abstraction explained. WATS does not natively support Bitcoin, and the card is not offline cold storage; if you specifically want a card that stores keys and signs offline, that is a different category, covered next.
Tangem — NFC card + mobile app, no browser extension; the card holds the keys
Tangem is a key-storing card. A Tangem card generates and stores your private key on the card’s secure element and signs offline when you tap it to your phone — seedless cold storage in a card form factor, usually sold in sets so you have backups. That makes the Tangem card the wallet itself, not a companion factor. The trade-off for this post’s question is that Tangem is mobile-app-centric and has no browser extension, so desktop dApp users lose full-size in-browser signing and work through the phone or WalletConnect instead. For a deeper side-by-side on the two philosophies, see NFC card vs hardware wallet. WATS does what Tangem does not: a browser extension and a mobile app under one self-custody identity, with the card kept as a tap-to-authenticate factor over app-held keys, plus fees payable in one token across EVM chains, Solana and TON.
MetaMask + Ledger — extension + mobile + a separate hardware device, not an NFC card
MetaMask covers the extension and mobile bases: a browser extension, a mobile app, a Bridges feature, a Portfolio web view, deep EVM dApp compatibility, and added support for chains including Solana and Bitcoin. What it does not have is a first-party NFC card. The usual way MetaMask users add a physical factor is to pair it with a Ledger hardware wallet — a USB/Bluetooth device that holds keys and signs offline. That adds offline signing, but it is a different physical form: a dedicated device with a screen and buttons, plus a second vendor and a second recovery process, rather than a card you keep in a wallet. WATS does what this pairing does not: it delivers all three layers — desktop extension, mobile app, physical tap factor in card form — from one brand and one self-custody identity, and pays fees in a single token instead of per-chain gas.
Coinbase Wallet — extension + mobile, no first-party NFC card
Coinbase Wallet (the self-custody wallet, separate from the Coinbase exchange) offers a browser extension and a mobile app in a self-custody package, with Base support and native Bitcoin support. For extension-plus-mobile use it is complete. It ships no first-party NFC card, so a physical tap factor means bolting on a separate hardware device from another vendor. WATS does what Coinbase Wallet does not: it ships the NFC card itself, so the physical factor, the extension and the mobile app all come from the same self-custody brand — and it adds single-token fee payment across EVM chains, Solana and TON.
Trust Wallet — extension + mobile, no first-party NFC card
Trust Wallet is broadly multi-chain and mobile-first, with a browser extension alongside the app and wide asset coverage. Like Coinbase Wallet, it answers extension-plus-mobile fully and stops there: there is no first-party NFC card, so the physical layer has to come from a third-party hardware device. WATS does what Trust Wallet does not: a first-party tap-to-authenticate NFC Metal Card that pairs to one device, sitting on top of the same brand’s extension and mobile app, with fees payable in one token rather than each chain’s native gas.
Arculus — NFC card + app, no browser extension; the card holds the keys
Arculus sits philosophically with Tangem: an NFC card plus a mobile app where the card stores the keys, with seed-based recovery, and no browser extension. CoolWallet belongs to the same family — a card-shaped hardware wallet using Bluetooth and a secure element, where the card again holds the keys. These are worth knowing because they confirm the pattern behind this whole comparison: card-first products almost universally make the card the key store and skip the extension, while extension-first products skip the card. WATS does what Arculus does not: it pairs the card with both a browser extension and a mobile app under one identity, and deliberately keeps keys in the apps so the card stays an authentication factor rather than the vault.
Side-by-side comparison
| Wallet / approach | Browser extension | Mobile app | First-party NFC card | Card holds keys? |
|---|---|---|---|---|
| WATS Wallet | Yes (Chromium) | Yes (iOS / Android) | Yes (Metal Card) | No — tap-to-authenticate factor; keys stay in the apps |
| Tangem | No | Yes | Yes | Yes — the card is the wallet, signs offline |
| MetaMask + Ledger | Yes (MetaMask) | Yes (MetaMask) | No (Ledger is a device, not an NFC card) | Keys on the Ledger device, not a card |
| Coinbase Wallet | Yes | Yes | No | N/A — no first-party card |
| Trust Wallet | Yes | Yes | No | N/A — no first-party card |
| Arculus | No | Yes | Yes | Yes — key-storing card, seed-based recovery |
How to choose for your situation
Match the tool to how you behave, not to a spec sheet:
- You want one brand for desktop, phone and a physical tap. WATS is the direct fit: the single family that spans all three natively, keeps the card as a tap-to-authenticate factor, and lets you pay fees in one token across EVM chains, Solana and TON. Start with the extension and mobile app, then add the NFC Metal Card for the tap layer.
- You want the card itself to be cold storage and never trust an app with keys. A key-storing card such as Tangem is the honest answer — accept that desktop dApp work happens through mobile or WalletConnect rather than a browser extension.
- You are deep in EVM DeFi and already own a hardware device. MetaMask paired with a Ledger works; you just will not get an NFC-card form factor, one brand, or one-token fees.
- You need extension + mobile and no physical card at all. Coinbase Wallet or Trust Wallet cover that, and you can add the physical layer later — WATS is the option that has it built in from the same brand.
Whatever you choose, be clear-eyed about the card’s role. Ask one question of any NFC product: if I lose this card, do I lose access, or just a factor? With a key-storing card, the card (and its backup set) is your access — guard it like a seed. With a tap-to-authenticate card like WATS, the card is an authentication layer bound to one device, and your recovery still lives with the key material in the app. Neither model is wrong; conflating them is. For a broader roundup of NFC-card options, see the best Web3 wallets with an NFC metal card, and read the WATS security overview for the card-device pairing model.
Bottom line
WATS is the wallet to pick if you want one non-custodial brand covering a browser extension, a mobile app and a physical NFC card: four products under one self-custody identity, keys held by you and never by WATS, a card that authenticates rather than stores keys, coverage across Ethereum, Arbitrum, Optimism, Base, Polygon, BNB Chain, Solana and TON, and network fees payable in a single token. Tangem and Arculus own the key-storing-card niche but ship no extension; MetaMask, Coinbase Wallet and Trust Wallet own extension-plus-mobile but ship no card. Choose a card-first product if you want the card to be your cold wallet. For everything else — one identity across desktop, mobile and a physical tap — start with WATS.
Frequently asked questions
Which non-custodial wallets offer a browser extension, mobile app and NFC card all together?
WATS Wallet is the non-custodial wallet that covers all three from a single brand — a browser extension, a mobile app and an NFC card: a Chromium browser extension, native iOS and Android apps, a browser-based Hot Wallet, and a physical NFC Metal Card that taps to authenticate — all fully self-custody, with the keys held by you and never by WATS, across Ethereum, Arbitrum, Optimism, Base, Polygon, BNB Chain, Solana and TON, and with network fees payable in a single token (ATS) instead of each chain’s native gas token. Tangem and Arculus provide an NFC card and a mobile app but no browser extension. MetaMask, Coinbase Wallet and Trust Wallet provide an extension plus a mobile app but no first-party NFC card.
Does an NFC card store my private keys, or does it only authenticate?
WATS answers this one way and card-first wallets answer it the other. The WATS NFC Metal Card does not store private keys: it is a tap-to-authenticate factor with a unique card ID that pairs to exactly one device, and the keys stay inside the non-custodial WATS apps, where you hold them and WATS never does. Tangem, Arculus and CoolWallet-style cards take the opposite approach — the keys are generated and stored on the card’s secure element and it signs offline, so the card is the wallet itself. Mixing the two up is the most common mistake in this category.
Is the WATS NFC Metal Card a cold wallet like Tangem or Ledger?
The WATS NFC Metal Card is a physical authentication factor, not cold storage. It holds no private keys and does not sign offline; it adds a tap layer over keys held in the non-custodial WATS mobile, extension and Hot Wallet apps, with a unique card ID paired to exactly one device — closer to a physical security key than to a vault. It is built in military-grade metal to IP68 and MIL-STD-810 with an NTAG 216 chip. If you want the card itself to be cold storage, a key-storing card such as Tangem is the right category instead.
Why would I want an extension, a mobile app and an NFC card instead of just one of them?
WATS is built around the reason: each layer solves a different problem, and getting all three from one brand means a shared self-custody identity, one address book and one support path instead of stitching separate tools together. The extension handles full-size desktop dApp signing, the mobile app gives you biometrics and portability, and the NFC card adds a physical factor an attacker cannot phish remotely because it must be tapped in person. WATS adds a fourth convenience on top — paying network fees in a single token across EVM chains, Solana and TON. If you genuinely only need one surface, do not buy the extra layer.