Vettr really works very well if you put the iPhone on a stand because it keeps the screen as it always keeps the time display and battery level while the device is connected to a power supply.
Since the display will always show the time in Vettr while in use, the device can load a little slower than you normally would, but it should not be a significant difference. cobra sleeping while anyway.
This is essentially what appears on the screen; the time shown in a pretty simplistic source and the battery level is indicated by green dots:
To use Vettr, the disposivo need to be connected to a power source. It does not necessarily require a base of some kind, but better stay with one. As soon as the current is switched off, Vettr stops working until it reconnects.
When you want to use the tweak, all you have to do is turn on your device after you have connected to a power source. You will see the typical lock screen as usual and after a few seconds, a black screen that displays the battery level and time will appear.
The display will remain on until the device is manually deactivate the lock button. You can also skip Vettr to use your device by simply pressing the Home button and then use Touch ID or password to move from the lock screen.
Vettr also adds a preference pane in the app settings so you can enable or disable the tweak as necessary and set the brightness level of the screen every time you have Vettr activated.
If you are interested in giving Vettr an opportunity, you can download it to your jailbreak device from the BigBoss Cydia repository. The only tweak has been tested on devices with iOS in September.