Drive a rover on Mars. Pay by the second.
A rover on a line like any other. You pay it five seconds at a time, straight to it, over a Bitcoin payment channel, and every command you give rides inside the payment that pays for it. Stop paying and it holds, then drives itself home along its own tracks. It also keeps its own limits whatever you pay: it will not drive into the crater. Mars is simulated; the channel and the money are real.
Scan to deposit from an external wallet
Every command travels inside the payment that pays for it, sealed so that only the rover can read it, and the rover obeys it only once the payment checks out: the payment's own signature is the only authority. Each payment also carries the running hash of everything accepted so far, so each one, and the settlement on chain, binds both sides to exactly what was commanded. The rover keeps its own limits whatever it is paid. It never sees your wallet key, and this site never holds your money. Patent pending. Watch the rover live.