NOWPayments is described as 'Start accepting Bitcoin, Litecoin, Ethereum, stablecoins, and many more cryptocurrencies with native integration into your platform or a neat widget' and is an app in the Business & Commerce category. There are nine alternatives to NOWPayments for a variety of platforms, including Online / Web-based, Android, iPhone, SaaS and Mac. The best alternative is BTCPay Server, which is both free and Open Source. Other great apps like NOWPayments are CoinPayments (Paid), Plisio (Free Personal), iBTC (Free) and CoinGate (Paid).
Plisio Cryptocurrency Payment Gateway Plisio is a Payment Service Provider (PSP) for merchants accepting crypto. Plisio enables your customers to pay with Bitcoin, Litecoin, Ethereum, Dogecoin, Zcash and 50 other cryptocurrencies.