It should be noted that my eldest daughter will be six in July 2015.
I’ve highlighted my favorites, but there are no links as I do not know what OS you are running. Just copy and paste. .
Beyond Cats Math. Individual apps for grades 1, 2, and 3.
The Foos
Kodable
Tower Math
Up to 100
Endless Alphabet
Endless Numbers
Moose Math: Duck Duck Moose
Lightbot Jr. and Lightbot
Marble Math Jr.
Montessori Math City
Montessori 1st Operations
Monument Valley
Thinkrolls and Thinkrolls 2
Motion Math Fractions
Scratch Jr.
The Sight Word Adventure
All apps from L’Escapadou
PBS Kids
Raz A-Z