Prueba de optimización para móviles (google)
https://search.google.com/search-console/mobile-friendly
iPad Peek
http://ipadpeek.com/
Mobile Phone Emulator
http://www.mobilephoneemulator.com/
MobiReady
https://ready.mobi
Manymo
https://www.manymo.com
mobiletest
http://mobiletest.me/
Responsivepx
https://responsivepx.com/
responsinator
http://www.responsinator.com