In need of any programs or platforms that track prices related to my average price

Curious to see if there are any resources (paid or free) that have the capability of me entering my portfolio and average cost/share. From this program, it would alert me when my owned stock is say, 10% below my current average.

My portfolio is pretty beefy, and checking average versus current prices on a day to day basis is pretty time consuming. Any resources, apps or programs that would do this autonomously?

Thanks for any help!