This is solving the wrong problem. If a traffic light can turn green at a whim, for any arriving app user, the intersection is not busy enough to have a traffic light. Then the traffic light should be removed or switched off for those times, instead of getting a very expensive (I presume) upgrade. If the intersection is busy enough so that people are waiting on all (or most) stop lines, then simpler traffic density sensors are a better, less invasive, far cheaper, and more privacy-preserving option.
…which in practice tend to be more expensive to implement and maintain. Systems like this one can work because they take advantage of highly available commodity infrastructure.
In the most cases, you should imho skip the traffic lights all together and use a roundabout. Automatically balancing, can work to large capacities (not as large as traffic lights, but visit France if you need to see how much traffic they can handle). No fragile electronics, no power consumption, less maintenance, less accident-prone (really!).
Yes roundabouts generally work well despite the fact that many American drivers seem to have problems with them.
There are some traffic patterns where roundabouts don't do well. I've seen the following. Imagine a four way roundabout with north, east, south and west. Predominate rush hour traffic is towards the east. Heavy traffic entering from north. More entering from west. Most exiting at east with very little going around beyond west. Entering from south can be nearly impossible since they're waiting for a break from both north and west.
