Divergences are not indicators per se.
Divergences can be observed across assets or between an asset's price and an indicator.
Lets focus on the latter, as it seems that that is what you have in mind. And lets think of divergences between price and MACD to keep things specific and thus simple.
A hidden divergence is a pullback entry of sorts. Not useful in my experience.
A regular divergence is a measure of momentum not going along with price. Not useful for me, but I've worked with truly outstanding traders that trade mostly divergences. They would explain their success with the use of divergences, while I would say their edge lies somewhere else (tape reading, trade management, etc) and they are not aware of it. Now, for those who are into fading (i.e. going against the trend), waiting for a regular divergence can be helpful as it forces patience into the trader, and makes the trader only fade once the trend's momentum slowed down.
Just realized this post is under trading software section ... coding divergences is difficult and imperfect .... I would run away from any divergence indicators.
Hope that helps. Cheers.