在设备上对本机开发进行响应，是否过期?

I am not sure if this is a thing, or possibly and issue. I am hoping others have experienced it. But every time I put a dev build on my iphone through xcode, the app works fine on the device while unplugged from the computer for about a week. Then the app crashes at the splash screen. Every dev build of an app I have loaded on my device has done this. Even example apps I have downloaded from the web.I am not sure if this is a thing, or possibly a