I tend to think it's good when running in a browser but not when it's made mobile web app capable and running full screen without native controls. Unless it's a super simple single page app.
At the other end there are things like Instagram where you basically can't do anything on the website (can't sign-up, can't upload photos). Everything requires the app.
I absolutely hate jquerymobile, you should just make your website responsive with CSS media queries then pepper in a little bit of javascript to handle things like slide out navigations.
I tend to think it's good when running in a browser but not when it's made mobile web app capable and running full screen without native controls. Unless it's a super simple single page app.
At the other end there are things like Instagram where you basically can't do anything on the website (can't sign-up, can't upload photos). Everything requires the app.