Avoid: does not work on iOS. Shonky.
I saw the web site, it looked good, and there is an app for iOS, so I decided to pay for a month and install the app. I installed the Chrome browser extension as directed. Fine, it said it was installed. But I couldn’t see the extension in Chrome. After an hour or two research, I discovered that Chrome does not support browser extensions on iOS. So, without the browser extension the app is no more than Anki with a monthly subscription i.e. a rip off. It is dishonest to sell this product for iOS. Very shonky.