This research examines the effects of a computer reading program as a supplement to classroom instruction for Kindergarten students across Study 1 and Study 2 (N = 55 and 88, respectively). Students attended schools in suburban settings and all students received their typical balanced literacy programming. Students in the treatment condition used the Ooka Island computer program (Scholastic F.I.R.S.T. [superscript TM], 2017) as a supplement to classroom instruction. The computer program targets phonological awareness, word reading, and reading comprehension. Across both studies, students in the treatment group (n = 26 and 49 for Study 1 and 2, respectively) had better outcomes for phonological blending, word reading, reading comprehension, and book-reading levels than the business-as-usual control group (n = 29 and 39). There were no group differences for phonological segmentation. The findings demonstrate that early-reading computer programs, such as Ooka Island, have the potential to supplement classroom instruction toward building foundational reading skills.