Can I Buy/Sell on the Mobile App or the Web? Quidax Support September 28, 2020 08:16 Updated You can use the Quidax mobile app 📱 (Apple and Android) or the website 💻 to buy or sell BTC/USDT. For the website, you can also use the Instant Buy/Sell or the Order Book Exchange. Related articles How do I know if I win? What is the Bitcoin (BTC) to USDT (BTC/USDT) Trading Championship? 🤔 Can I withdraw without verifying my identity? Why did my withdrawal fail? What is the exchange rate on Quidax?