One of our favorites is the color game. I gave Makenzie my iPhone and then told her, "Go find something..."
Makenzie takes my phone around the house, finds something that is the color I stated and then takes a pic of it, showing me afterward. It's a simple game but she LOVES it!
We've also been doing some Tot School Printables. There are a few pages that she knows how to do on her own and some that she needs help for but I can sit while she does them.
Her favorites are the coloring page from 1+1+1=1, which she does on her own,
and the counting from Confessions of a Homeschooler which she does mostly on her own.
One final thing that I just recently tried were "themed" baths. I found a pin on Pinterest called "20 Busy Mama Baths." So far we've only done the bath paints one, but it lasted for 45 minutes! I just put shaving cream in a muffin tin and colored the shaving cream with food coloring. Then gave her a paint brush but she mostly just used her fingers. The clean up was SO easy and it gave me 45 minutes of relaxation while she was still being stimulated and not on the iPad or watching TV. The nice thing for me is that our master bathtub is visible from our bed so I laid at the foot of the bed and watched her while I read a book.
I am feeling SO much better and am so thankful to be able to be back on a pretty normal schedule but I'm sure I'll need to utilize these again during the end of the pregnancy when everything aches and I'm exhausted again. :) Do you have any activities that you utilize for your kiddos when you're down for the count?