Here's a fast way to draw on a screenshot on your iOS device.
Since iOS doesn't let you do this natively, you will need to download a third-party app.
There are a few options, but if you're like me and want a beautifully designed, easy-to-use app, I recommend spending a couple dollars on Atom Draw - it's a beautiful app with no ads or in-app purchases.
You can also do a quick search for free alternative apps, but most of them are clunky, filled with ads, and just gross.
To take a screenshot anywhere on your iPhone (or iPad or iPod touch):
• Press and hold the power button, and then tap the home button.
The screen will flash white, and a screenshot will now be saved in your Camera Roll, inside Photos.
A good drawing app will let you quickly add a photo. Atom Draw makes it simple with big fat buttons, so you can jump right in to editing your screenshot.
You can do things like:
• Draw Lines or Arrows
• Circle something important
• Make Notes / Annotate
Zoom right in, pick the right color and brush size, and write on that screenshot!
When you've finished your work of art, save the screenshot and share it out to social media or email or text, or WHEREVER!