Kindergarten Addition Lite is a free demonstration release from I Did It Learning. Please look for Kindergarten Addition for the full paid ($0.99) version. This application teaches addition with numbers 0 through 4 where the answer is in the range of 0 through 7. 3 different activities are used to teach addition through visual cues with a 4th activity which removes the cues to confirm the skill has been mastered.
There is a bonus mouse maze stage for kids and there are very detailed visual progress screens for parents or teachers to see how their kids are doing.
This application has settings for speaking in either English or Spanish.
This software has been tested on preschool and kindergarten age children as well as special needs children. In all cases, it has proved very effective in teaching kids the basics of addition.