I am an educational specialist who develops science projects and programs to supplement homeschool. I have multiple stem degrees and am currently in a masters program for curriculum development. I teach/develop in both California ngss compliant supplemental programs and Montessori programs

In 2018 a lot of people in my industry changed to paid models. I feel this had to do with a gross lack of compensation industry wide and the rising need for ngss compliant programs.

You can honestly find good programs for children preK to pre university and beyond on Pinterest. This has been a mecca of educators sharing resources especially those that supplement their lesson plans.

I would begin searching by subject matter. Science is a very broad term. 'kindergarten chemistry water" "plant lab 2nd grade" "home dissection lab of x animal 7th grade" "egg drop physics at home"

My personal favorites for very young children that get them interested in very deep science are pH labs. You use a universal indicator (cabbage juice is fine as long as it's fresh) and test various substances. You have them blow bubbles in an indicator and water solution and have them draw conclusions based on their previous observations. Let them come up with their own pH exploration with safety guidance.

I also enjoy the iodine clock with timers and different ratios of ingredients for junior high students.

For physics with very young children I love 5 simple machines. They build catapults, simple water wheels with straws and cups, marble mazes with ramps and whatnot out of old food containers and cardboard boxes.

Nasa has released some great student programs to explore outdoor science. I've done their build a weather station at home with home materials many times with students from k to high school. Then they monitor and report their findings to a weather reporting website and do some citizen science

Can't hurt with early naturalist work.inaturalist and taking them outdoors on hikes to observe and catalog is a good way to hook them on bugs birds and flowers and start to understand the functionality of our species systems