The Cashrou extension for Chrome recognises a checkout or a renewal page and offers to add it, with the merchant, amount and cadence already filled in.
The reason your subscription list is wrong is that nobody opens a finance app while buying something. The extension is there instead.
Merchant, price and billing cadence are pulled from the page you are already looking at. One click to save.
A renewal confirmation or a price-change notice on screen is offered as an update to the subscription you already have.
The extension reads the page you are on to fill the form. It does not upload browsing history and it does not run on pages where there is nothing to add.
Saved from the browser, it appears in the app immediately and is picked up by the next payday routine.
The extension is quiet until there is genuinely something to record.
The extension is on the Chrome Web Store. Everything it captures can also be added by hand in the web app today.
Seven days free on the web app. $6.99 a month or $49.99 a year after that.