docs: Update 110.user-onboarding.md (#363)

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# Description

Adding Openfort

## Linked Issues

NA

## Additional context

---------

Co-authored-by: Antonio <[email protected]>

Author: joalavedra

content/00.zksync-era/60.ecosystem/110.user-onboarding.md

@@ -6,6 +6,34 @@ To drive mainstream adoption, it’s crucial to offer intuitive solutions that r
 
 Providing well thought out end-to-end wallet interaction flows is a key approach to make Web3 more accessible for everyday users.
 
+## Openfort
+
+[Openfort](https://openfort.io) is an open-source alternative to wallet infrastructure solutions.
+
+### Openfort Kit
+
+[Openfort Kit is a developer toolkit](https://www.openfort.io/docs/products/kit/react/quickstart) to integrate user onboarding and wallet connector.
+
+- **Plug-and-play UI Components**: Prebuilt, customizable authentication and wallet connection flows that can be deployed in minutes, not weeks.
+- **Developer Experience**: TypeScript-ready, wallet-standard libraries and easy integration with frameworks like React, Next.js and Vue.
+- **Full Customization**: Predesigned themes or the ability to fully tailor the UI to match your brand.
+
+### Invisible Wallet
+
+[Invisible Wallet](https://www.openfort.io/docs/products/embedded-wallet/javascript) enables applications to create a wallet embedded in the application.
+
+- **Embedded Non-custodial Signer**: Secure, self-custodial wallet creation and signing for users, with no need for browser extensions or external apps.
+- **Funding Support**: Users can onramp their newly created wallets with traditional methods or depositing crypto.
+- **Key Export**: Users can always export private keys, allowing them to take the wallet with them.
+
+### Cross-app Wallet
+
+The [Cross-app Wallet](https://www.openfort.io/docs/products/cross-app-wallet/setup) creates branded, interoperable wallets that work across multiple apps.
+
+- **Ecosystem SDK**: Build your own wallet SDK that can be integrated across your suite of apps, ensuring users have a consistent identity.
+- **No App or Extension Required**: Users can create and use wallets instantly via iFrames or embedded flows, compatible with any EVM chain.
+- **Modern Standards**: Supports the latest Ethereum standards (EIP-1193, 6963, 7702, 4337, and more) for broad compatibility and future-proofing.
+
 ## Reown (prev. known as WalletConnect)
 
 **[Reown](https://reown.com/?utm_source=zksync&utm_medium=docs&utm_campaign=backlinks)** gives developers the tools to build user