IXL is a great practice tool to get students to improve various skills without having it feel too much like work. IXL presents students with problems that vary difficulty based on whether students answer them correctly or incorrectly and provide detailed explanations for the problems students get wrong. The desktop version of IXL offers practice for math, language arts, science and social studies, but so far the only subject available on the app is math. A free thirty day trial is available to see if it works for your class.
Subject: Math, Language Arts, Social Studies, Science
Grade Level: Pre K-12
Price: $249/year for a class of 25 students, more for larger classes