Educators are rethinking how best to use the summer to help students improve academic proficiency rather than lose a grip on it—especially students who struggle academically or lack access to educational resources during the break.

And teachers are finding technology, if harnessed correctly, can play a crucial role. Schools may offer a fully virtual program targeting one or two subjects, for example, or a broader summer academy that incorporates bits and pieces of technology to blend summer school with summer camp. Regardless of the format, some educators find that technology gives them the opportunity to make instruction more flexible and personalized than it is during a school year bound by curricula and state testing requirements—and...