Spoiler- 6 in the top row - 3 in the time (3:33), 2 in the battery percentage (33%), and there is a very small 3 to the right of the battery icon.
- 9 in the phone number typed out - 8 obvious ones, there is a small 3 hiding in the 3rd three from the left
- 6 in the number pads - The 3 key, the letter I in the 4 key replaced with a 3, the number 8 replaced with a 3, and three 3's are in the asterisk key
- 2 in the bottom question ("number 3", "93%")
Total comes to 23 3's.
Due to the image quality, I cannot tell if there is a number next to the Sprint "WiFi" icon to the left of the time. It appears to be the number 1.
Also, I did not count the 3/5 dots to the left of the word "Sprint".
I'm not a big fan of the two small 3's since those are difficult to make out given the poor image quality.