responsivepx lets you specify viewport width and height so you can test your site in a variety of simulated screens. I added it to my bookmarks bar.
Via Jen Simmons, who does a great job on The Web Ahead.
Open source apps (not yet 1.0)Evergreen •
What I work on at OmniThe Omni Show • OmniFocus for Mac
brent.micro.blogFrontier Diary • Swift Diary
Vesper Sync Diary • How Not to Crash
Apps I’ve MadeRSS • JSON Feed
© 1999-2018 Brent Simmons
Made in Seattle. Go Hawks!