Sure! Here are some US-based real device testing sites and online platforms for mobile app live testing that offer free options:
Firebase Test Lab by Google: Firebase Test Lab provides a wide range of real devices for testing Android and iOS apps. It offers both free and paid options.
AWS Device Farm: AWS Device Farm is a cloud-based testing service by Amazon Web Services that allows you to test your app on real devices. It offers a free tier for limited usage.
BrowserStack: BrowserStack is a popular cross-browser testing platform that also provides real device testing for mobile apps. They offer a free trial that allows limited access to their device cloud.
Experitest: Experitest offers a free trial of their cloud-based testing platform called SeeTest. It supports testing on real devices and emulators.
Kobiton: Kobiton is a mobile testing platform that provides access to a variety of real devices for app testing. They offer a free trial that allows limited usage.
Perfecto: Perfecto is a cloud-based testing platform that offers real device testing for mobile apps. They provide a free trial with access to real devices.
Sauce Labs: Sauce Labs is a cloud-based testing platform that supports real device testing for mobile apps. They offer a free trial with limited access to their device cloud.
Please note that the availability of free options and the specific devices supported may vary over time, so it's always a good idea to check their websites for the most up-to-date information and pricing details.
