Check out CT ART.
whats the best free chess apps

The chess.com app is better than most for all these things. Like all apps, it lacks some of the functionality of the website, and like most apps, some of the best content is behind a paywall.
For tactics on iOS mobile devices, nothing beats TacticTrainer, which is less than $6. Chess.com tactic trainer is a little. ore robust, but requires premium membership unless you are satisfied with very short daily training sessions.

There's an app called Chess by cnvcs on Google Play. It has 38,000 tactics puzzles, organized in levels of difficulty. It also can be linked to any other phone with the same app, by Bluetooth or WiFi, so people can play each other, each using their own phone. It also does online stuff. I have it, Droidfish, and the Chess.com app on my smartphone.

Of all the computer chess stuff, freeware Lucas Chess is excellent. I paid for Chess King but tend to use Lucas Chess much more often.

Because free is good plus im cheap
I've used a lot of free apps. The only free apps that are worth what you pay for them are connected to pay sites, like chess.com

any thing that shows. Chess holes. Holes in position. Or squares Controled !!!
if you want to learn about chess holes and how to take advantage of them, there are plenty of free videos on youtube that will tell you how to spot them.
if you are looking for an app that highlights these as you play or something, i feel that that would be a waste, as your goal is to be able to spot these for your self. It would be like putting training wheels on your bike after you've learned to ride.
Anyone know of any good chess apps. I like the droidfish app. But im looking for app with cool features. Or and training exercises or prorams.