Cairn

Cairn is a Bitcoin-only Android app for people who care about the signal,
not the noise. Pin widgets to your homescreen for live price, mempool, fees,
on-chain indicators, and your own watch-only stack. Open the app for the
full dashboard — Cycle Lab composite, network depth, ratio context.

Watch-only by design. Paste an xpub or output descriptor — Cairn tracks the
balance, UTXO state, and FIFO / LIFO / HIFO cost basis. Keys never enter the
app. Cairn never signs Bitcoin or Lightning transactions; if you want to
spend, the app deep-links out to your real wallet.

Point at your own node. Override the endpoints for mempool.space, Esplora,
BRK, and every other data source.

No ads, no analytics, no KYC. We collect nothing. The app has no backend —
every byte of your data stays on your device.