My wife and I used this on a recent trip to Dublin from the USA. It was a real lifesaver! We used it many times and would recommend it to travelers like us.
That said, there are some things to note that could be improved. The ETA shown on the map is essentially meaningless, and we learned to ignore it. Also, the location data for individual drivers is not great. In one case, LynkTaxis told us our driver was on the opposite side of Dublin and would take 33 minutes to reach us (!!), but then he pulled up 2 minutes later.
Leaving aside the ETA inaccuracy, we always got a driver eventually, and found that if we used the pre-booking feature, the results were excellent. Lynk always called us if there was a delay, which was nice.
In summary, if you’re American and think this is Lyft or Uber, change that expectation. This works differently. But if you’re willing to view this as what it is (a taxi booking app), and have patience, you will be rewarded.