I ended Friday here:
I got a lot of great responses from a ton of great people (thank you) bu then there was this:
To be honest, if Christopher Danielson wanted to come and teach a guest lesson on the history of writing instruments for crying out loud, I’d be bouncing-off-the-walls excited. I think I did an ok job staying calm while he was there. But goodness was this a treat for me and my students.
Professor Danielson taught one of my Master’s courses at the University of Minnesota about 11 years ago, and my first-year teaching self didn’t then appreciate the brilliance and talent of this man. I saw observed him in my classroom today, effortlessly and masterfully, assess my students their current level of understanding, guide them through an example and connect the new learning to their prior knowledge. Thank you, Professor. You helped me to develop better questions for my students.
And since I’m taking the time to thank Christopher, I want to show some gratitude to the other creators of the tool that has been a game changer in my and so many other classrooms: Desmos. Here are what rational functions used to look like in my classroom a few years ago.
I’d like to say this is better than nothing, but with misleading end behavior, I’m not sure it did us any good. 
Here’s the same graph in Desmos:
There’s so much more to this than just calculator display. Have you ever had a question about Desmos go unanswered? Ever? Have you ever used a technology tool in your classroom that was so intuitive that all students could feel successful using it? And finally, have you ever engaged with a staff of people who work more tirelessly and joyfully than the crew at Desmos, relentlessly improving their product to secure the positive future of mathematics classroom? As a small part of the online mathematics teacher community, I want to thank everyone at Desmos from the bottom of my heart for the shift they have helped create in so many classrooms across the country and for the difference they continue to inspire in mine.
Number Loving Beagle 
Thanks Megan for your post. If you don’t mind–I want to add my thanks in with yours. If it wasn’t for your post, I would probably only think this to myself, and nd not publicly express my gratitude. It’s the right thing to do–to thank those at DESMOS and all the others who so graciously share their ideas and their talent with kids all over.
Here goes. I was visiting in a class this afternoon and the teacher was having kids create tables and compare some functions. I asked if she had thought about using DESMOS. She insisted on pulling up some graphing software that looked like the one in your post. And it didn’t work. So, I suggested again–as nicely as I could–trying to be somewhere close to the spirit of Christopher Danielsen nice–that maybe DESMOS would work. We got it up on her smartboard–and a kid who had not really been engaging in the conversation for most of class, sits up straight and starts watching what was going on. The next thing I knew–he was up at the board doing stuff. DESMOS is amazing. And so are you for reminding me to say thank you to all the people who support me and let me help out in classes.
SUPER-SUPER-SUPER-LIKE!!!!!!!!!