Number search

Looking for a desktop or phone App for testing visual search in an 8 x8 array of single digits i e. 64 numbers. Varying fonts and font size. And overall size of the array. The subject looks at the array on the screen from 35cm.
Task: e.g. How many 3’s do you see?
Subject enters their score by clicking on a number from 0 to 9 that appear in a row underneath the array. App measures time taken from presentation of screen till response. i.e. response time.
Performance ( speed and no. of errors) is presented for each attempt
and average search time for 5 searches is presented together with total number of errors.
If possible