iPhone users, follow these steps if you receive the "Untrusted Enterprise Developer" prompt when installing the 55.com app.
————Please follow the steps below————
1. Go to Settings → General
2. Scroll down to the bottom of General and select "Profile" or "Device Management".
3. In the "Profile" or "Device Management" tab, you view the description file.
4. Click on the description file to see the details, then click trust on the description file.
5. The iPhone prompts a window asking if you trust the file -> select "Trust".
6. After you select "trust", the description file will look like the following image. Return to the desktop and click on the "55.com" application to open it normally.