A tool you can use to get basic stats about your Blue Archive gacha pulls. Enter how many 3* students you got on each 10-pull and click on the Add attempt button to add it to the stats. You can use the Remove button next to each attempt to remove it if you've made a mistake.

Tip: You can use this tool to display your pull stats in real time if you're recording or streaming your pulls by adding a Browser Source in OBS, cropping it to the stats square, and keying out the background.