Need to simulate low connectivity internet for my app

i need to simulate my app for low connectivity network where i found that some of my site worker using this app not successfully send data whenever the internet is low..the app is created for low and high internet connectivity but i have problem trying to simulate the scenario..this issue happend when 3-4 people submit data and one of the submission will fail..need app tester to help me find this bug so my developer can fix it