Built a small tool that tells you why your AWS bill changed each week

Over the past year I kept seeing the same AWS problem across founders and small engineering teams: the bill changes faster than people can explain it.
Usually nobody notices until month-end, and by then they're digging through Cost Explorer trying to figure out which service changed, what deployment caused it, and whether it's real growth or waste.
So I built a lightweight tool called ThinCost.
It connects to AWS using a read-only IAM role and sends a weekly email explaining what changed, which services drove the increase, potential waste, and concrete actions to reduce spend.
The goal wasn't another dashboard. It was: "Tell me in plain English why my AWS bill changed."
Setup is about 60 seconds: email + AWS account ID → deploy a CloudFormation stack → done. No stored credentials. No write access. Read-only permissions only.
Looking for a handful of beta testers running real AWS workloads. Happy to give free access for a few months in exchange for honest feedback.
→ thincost.com