portable outdoor security system recommendation, please

[Grace Sunshine]

We flipped a house with an outdoor swimming pool, which is 1.5 hours driving distance from my home. Currently, the house is listed for sale.  The agent is also far away from the house. 

Today I got a call from a neighbor, telling me that the water is outrunning due to the pool. Kids in the neighborhood jump over the fence and swim in our pool!!!!!!!!

I want to setup a security system to see the swimming pool and scare the kids away. Based on the information from Biggerpockets, I called http://simplisafe.com to see whether they have a system that we can buy and set up. They told us that they don't have such system. Anyone here have any suggestions for the security system to see the swimming pool without internet?

Thanks very much.