Take care, a phone has a lot of vulnerabilities when compared to best practices. Use with burnable amounts. But ya, it's an awesome app. I've been used to using mymonero.com for such purposes, and this much easier and more convenient. Add a hardware wallet for topping up, you are safe and versatile. SoonTM
Actually an Android phone is probably mores secure that a Windows PC because it runs all apps in a virtual machine. Of course though there's always the risk of your phone being stolen and went through if you don't have a password or gave the password to the person who decided to go through your phone.