This ASL Dictionary from the National Technical Institute for the Deaf is a modified version of their popular ASL Video Dictionary and Inflection Guide -- DIG. The program shows 2,700 signs and 650 sentences that demonstrate how signs change, or inflect, to convey different meanings. For example, modifications in hand movements and facial expressions can change the sign for help to mean help me, help them, help for a long time, etc. Afternoon can change to mean all afternoon, late afternoon or every afternoon. The sentences also show the full range of ASL grammar.
There is an option to show signs grouped into 24 categories: Countries, Animals, Numbers, States, Money, etc. As a self-test, users also have an option to choose when they see the English sentences simultaneously with the ASL sentences, or afterwards.