A comeback chest after three losses sells better than a random offer.
Wrong
Same conversion, more quits. Dropped the offer, added a hint instead.
A notebook for product bets
Write down every guess.The wrong ones become your edge.
Every plan is a stack of guesses about how people will react. Guessbook pulls them out, lets you mark what happened, and remembers every one you got wrong.
Free during early access · Web, iPhone and Android
- 01
A bigger day-one reward lifts day-two retention.
WrongWhat we changedNo change. Moved the reward to day three.
- 02
Losing feels like my fault, not bad luck.
Right4 of 5 testers blamed their own timing.
- 03
Players find the daily quests within 3 minutes.
Untested
How it works
- 01
Write the guess down
Before you build, write what you expect people to do. One plain sentence.
- 02
Test it
Playtest, ship, read the numbers. Then mark it right, wrong or unclear, and note what happened.
- 03
Keep the wrong ones
A wrong guess, plus what you changed because of it, is the most useful thing a team learns. Guessbook keeps every one.
Not just for games
Every plan is a stack of guesses about people.
Teams invite a colleague in their first week.
Unclear
Only 1 in 5 did. Too early to tell.
A price-first ad beats a feature-first ad on installs.
Right
18% more installs for the same spend.
Built to stay honest
Results can't be rewritten
Results are added, never edited. Change your mind and you add a new one; the history stays.
Every guess has a name
See who wrote each guess and who tested it, across the team.
Back to the source
A guess taken from a plan keeps the exact sentence it came from.