Cake Wallet's Free 'Cupcake' App Transforms Old Smartphones Into Secure Offline Hardware Wallets

In Brief

Cake Wallet launched Cupcake, a mobile app that transforms unused Android or iPhone devices into offline hardware wallets for Monero and Bitcoin, offering secure, cost-effective storage without shipping or personal data requirements.

Open-source cryptocurrency wallet with a focus on privacy, Cake Wallet introduced Cupcake, a mobile application that turns any unused Android or iPhone device into an air-gapped, fully offline hardware wallet for Monero (XMR) and Bitcoin (BTC). By eliminating shipping and supply-chain risks, as well as the requirement for users to provide personal information, Cupcake offers hardware-level security to individuals who have previously encountered obstacles related to cost, availability, or privacy. Support for Litecoin (LTC), including features such as Silent Payments and MWEB, is planned for release later this year.

“If you have an old phone in a drawer, you already own a hardware wallet,” said Vik Sharma, Founder and CEO of Cake Wallet, in a written statement. “Just install Cupcake, create or restore your wallet, and you’re protected. No courier labels, no customs forms, and no one collecting your address,” he added.

Cupcake’s Public Beta Offers Offline Cold-Storage Security For Monero And Bitcoin

Cupcake functions entirely offline, requiring no network permissions, ensuring that private keys remain stored solely on the device. Users have the option to perform a factory reset on an unused phone, disable all wireless features, install Cupcake, and set up or restore a seed. Once set up, the device signs transactions offline, while a view-only wallet in Cake Wallet, accessible from a daily-use phone or desktop, broadcasts the signed transactions using a QR code. Since the phone used for this purpose appears as a regular device, it avoids the attention that traditional hardware wallets might attract, thus enhancing overall operational security.

Cake Wallet noted that while this approach is not necessary for privacy or security, keeping a non-restored device online with Cupcake and separate is entirely secure. Offline signing is simply a more stringent ‘best-practice’ method for users who prefer this level of security.

“From Caracas to Kolkata, Cupcake brings true cold-storage security to places where dedicated devices are scarce, seized at customs, or priced far out of reach. Repurposing an existing phone also keeps e-waste out of landfills, proving that privacy, security, and sustainability don’t have to be trade-offs,” said Seth for Privacy, VP at Cake Wallet, in a written statement.

The public beta of Cupcake is officially launching today, with initial support for Monero and Bitcoin. Litecoin, including full integration of Silent Payments and MWEB privacy features, is expected to be added in the third quarter of 2025. Further support for additional assets, reproducible builds, and hardware-device integrations is planned for the fourth quarter of 2025.