Here is a link to an excellent article published by the NCLD (National Center for Learning Disabilities) giving an overview of various assistive technologies for students with learning disabilities. It explains what technology can (e.g. improve the speed and accuracy of work) and cannot do (e.g. it cannot make a learning disability go away) and how to decide which technology is best for a given student.
Below this article you will find more useful articles with related content, such as, apps to help students with organization, and apps to help students with dysgraphia and writing difficulties.