How can I generate iOS screenshots without using a simulator?

A popular solution to this problem is this automation tool called snapshot. It is apart of a suite of tools made to automate iOS and Android developments.

For relatively small applications though, the simulator isn't too bad.

If you developed your app using Cordova - you might be able to use a web browser to automate screen generation

And it looks like he just updated his post to talk about generating screenshots using Firefox. Even gives a node.js script someone can use to automatically sort out the images into folders.

I just tried it out on my app and it worked!

All you need to do is install Firefox and turn on the responsive mode in the developer tools. Then you can set your resolution, set the zoom to 200% and use the screenshot button to take a shot that meets Apple's guidelines.

Awesome!