I've been using ToDoist for about a year. It's great, meaning I can do everything I can possibly think of with this app regarding managing my tasks. Plus it's easily accessible via Chrome or Firefox and I can easily turn Gmail emails into to-do's. The only relatively minor issue: I don't use the Windows 10 App (I use it only in the browser) because there apparently is no way to adjust the font or screen size within the app; the default is too big for me.