Which app can I use to buy core?

I'm interested in purchasing some CORE cryptocurrency, but I'm not sure which app to use. Could you recommend a reliable and secure platform where I can easily buy Core? Ideally, I'm looking for an app that supports a variety of payment methods, has low fees, and offers good customer support. Also, it would be great if the app has a user-friendly interface and is available on both iOS and Android devices. Do you have any suggestions?