Stopwatch App Professional

The Stopwatch App Professional, running on several Connect IQ™-compatible Garmin devices, offers you a

stop watch with LAP/spit functionality.
timer functionality with count-down feature.

It is designed as a watch app (and not a data field) for following reasons:

Simple to install and use
Arbitrary feature enhancement possible
Circumvent that some watches (e.g. vivoactive™) can only display two Connect IQ™ data fields

Link to Stopwatch App Professional on Garmin App Store

This website provides further information regarding requirements, installation, getting started, supported data fields and features as well as frequently asked questions.