We create fun and useful Bitcoin apps.
Compare the current Bitcoin price to the Stock-to-Flow model and the 50% and 80% prediction interval lines.
Take a photo with the QR image which is generated to prove that you were alive at the current block height.
Experience the mining process yourself by creating a tiny time chain based on Proof-of-Work with a difficulty adjusment.
Sign messages with your own private key, or verify the messages of others. All using Bitcoin's secp256k1 elliptic curve.