Here is a list of free digital apps and websites students can access and use for remote learning! I have not tested all of them, but there are a few that preschool kids can use with adult supervision. 

https://docs.google.com/spreadsheets/d/1t3r618pd8MAi6V87dG2D66PtiKoHdHusBpjPKXgm36w/htmlview?sle=true#gid=0