Device drops WiFi & does not reconnect?
Apps do not interface directly with the device's WiFi controller; instead they are only able to request access to WiFi from the iOS operating system.
This request is made through a flag defined when we submit the app to Apple called UIRequiresPersistentWiFi. This flag tells the iOS that if a WiFi connection is available, that the app needs it to be maintained. It’s also why if the app is launched without a WiFi connection, you may see an alert on-screen asking if you’d like to connect to WiFi before proceeding.
If the app is unable to load a remote page due to lack of Internet connection, we continue to request that resource at regular intervals so that the app can recover automatically when the connection is resumed.
If a WiFi signal is dropped, the device may show an on-screen prompt asking if you would like to join other WiFi networks. While there is no way to exit the app through this prompt, it can be turned off in iOS settings by going to Settings > Wi-Fi > Ask to Join Networks > Off.
If your iPad regularly drops a Wi-Fi connection, Apple recommends several troubleshooting tips that can help you fix the problem.
The other option would be setting up a wired Ethernet connection, which recently became an option with Apple's introduction of a powered Lightning USB adapter. While currently marketed as a camera adapter, Apple execs took time at the March 2016 event where the adapter was introduced to call out the option to use it for Ethernet or other powered USB accessories, which means that this use case should be supported moving forward. More on how to set this up here.