Great question! I take screenshots on my Mac’s native screenshot tool. For the illustrations, I’ve been trying a few tools lately, but I like Apple Keynote the most. I love how fast Keynote allows me to put ideas on the page. When I need more power I go for Photoshop and when I’m on the move using only my phone, I use Canva.
Keynote is the most underrated tool out there in my opinion. Especially for animation. If you haven’t already, do check out an advanced Keynote animation tutorial on YouTube. I couldn’t believe how much it could do—especially for makeshift UI animation.