Everyday for Android Wear is digital watch face with big digits and second indicator.

Its main purpose is to quickly read time in a glance with higher than minute resolution - so this watch updates time every 20 seconds instead of only once a minute.

The extra screen updates doesn't result in any noticeable battery drain (no more than 5%). It also works and looks great on Sony SmartWatch 3 thanks to transflective lcd. It is not suitable (burn-in protection may not be enough) for OLED.

There are some configurable options: 12/24 hour modes, white on black or inverted, font size and typeface, font outline (because of background support), and few other things to toggle (date, seconds, top ambient battery line).

Everyday Watch Face also allows you to have custom clock background. Just share any image on your phone with "Everyday Watch Face" and it will be set as the background.

Support thread: http://forum.xda-developers.com/android-wear/development/everyday-watch-frequent-time-updates-t3021982