With the new release (as of Dec 6th 2016), you can save a group of "Sessions" with logins stored to a Project, which you can launch with the click of a button. "Projects" eliminates the need to spend time setting up your workflow every day, so you can get right to work.
Believe it or not, Safari has amazing dev tools, To enable them, go to the Preferences -> Advanced -> Show develop in the menu bar. There are many many options to help you with mobile site development, and much more.
Safari has a feature called handoff. This allows you to have a tab open on your computer, turn on your phone and swipe up on the Safari logo in the bottom left corner. Unlock your phone and the tab should be open.