Trial Radar

A free trial turns into a charge simply because nobody keeps the cancel date in their head. Trial Radar closes that gap inside Gmail. The Chrome extension reads the subscription, trial, and renewal emails you already have, lists what is about to charge in the next seven days, and takes you to the right cancel page in one click. It is free, needs no account, and installs from the Chrome Web Store.

The product is built around one line: your mail never leaves your device. There is no backend, no account, and no telemetry, and every email is processed locally in the browser. That is not a promise buried in a privacy policy: a build-time guard scans the source and fails the build if any committed file contains a network call or an address other than mail.google.com. The extension stores only what a subscription record needs (service, amount, charge date) in the browser's local storage and never keeps raw email text.

Under the hood it is a Manifest V3 extension written in TypeScript on the WXT toolchain. A content script reads the open Gmail page through InboxSDK, a DOM-free extraction core turns emails into records, and the cancel resolver picks the target in a spoof-resistant order: the canonical URL from a bundled community dataset first, a link from the email itself second, a pre-written cancel email third. That dataset is maintained in the open on GitHub under CC0 and is baked in at build time, so even dataset updates need no network access while the extension runs. Every release passes a test suite, a manifest verifier, and a scripted browser run over the popup and the Gmail page.