Shop at ZARA or H&M? I've launched a sizing solution

Hi everyone, a month ago my co-founder and I launched efitter, a Google Chrome extension and chatbot that uses your past orders to predict your size when shopping online. We're live on womenswear ranges at ZARA and H&M (expanding to more retailers very soon).

We're trying to gather as much feedback as possible so if you shop at either brand, please give it a try! It was designed to work seamlessly in the UK so I'm particularly keen to hear from people around the world so we can improve on it. Thanks!