Two dials control the whole experience: how long a scroll session lasts, and what a toll costs you in knowledge.
Your allowance is the length of one uninterrupted scroll block: 5, 10, 15, 20, or 30 minutes. When it runs out, the gate comes down and one correct answer buys the next block of the same length.
10 minutes is the recommended default. It catches you today, not next week. Five minutes suits the truly committed. Thirty is for people who mostly want a receipt of where the evening went.
A few details:
Pick what you actually want to know. Six topics ship today, each with roughly 160 questions:
Switching topics is instant and safe: the new topic starts at the next toll, and your streak carries over. Questions get gently harder as you answer correctly and step back down when you miss, so the toll stays a toll, not an exam.
Want a topic we do not have? There is a request field right in the app (during setup and under the topic sheet). Real humans read those, and requests steer what gets added next.