Why can I not install more than three apps?

Question

I have just started learning how to make iOS apps, and am using the free personal developer account.

I have made four apps so far, but do not seem to be able to inst

Answer 1

For me by removing unnecessary provisioning profiles from the device.

1. In the Xcode go to Window → Devices and Simulators.
2. Right click the device you are unable to install app.
3. Delete some provisioning profiles.

Clean App and then run will work.