There are many websites available for students to practice their literacy skills. Here are a few that you've shared with us. If you are looking for ways to have your students practice high-frequency words online while at home or in the classroom, check them out and see if one or more will meet your needs.
Sightwords.com provides students with flashcards and games so they can practice and learn Dolch and Fry sight words.
Reading Games from Education.com will engage preschool through grade-one students in prereading, alphabet, phonics, and sight-word games. Many are free.
PrimaryGames.com has an assortment of free reading games for preschool through grade-three students.
In addition to games for grades K–5, ABCYA.com has a Dolch sight-word BINGO game students can easily play by themselves.