More traditional educational apps?
Many of the curriculums have their own websites or online activities that go along with the textbook so you could use both. Sites like Dreambox Learning can help individualize instruction for your child as well. We use DuoLingo exclusively for teaching Spanish because we didn’t find a “traditional” curriculum that fit our needs.
Here are a few educational sites to try: Khan academy, math playground, spellingtraining.com, Hoffman Academy piano lessons (there are printable resources to buy but the videos are free). We used allinonehomeschool.com for a while, which is a complete curriculum that is built around free online resources (the creator was a missionary in the Middle East and could not access homeschooling resources from her area).
Free apps: moose math or pet bingo (for elementary school kids) Piano Mæstro and Piano Dustbuster, DuoLingo
See if your library has the Libby app or Flipster. Both give you digital access to your local library’s books and magazines. Hoopla is also provided for movies and educational videos, but there might be a limit on monthly downloads (our library’s limit is 4 vids per month).
I hope that helps!