We've tested Blue and found it to be quite nice. The UX is well thought out. The app is powerful. However it requires some work to set it up properly. It shines with teams, and there are simpler tools for individuals. We particularly liked the automation tools which can be found in other project management tools at a much higher price range. Plus you get unlimited storage.

We wrote a review in French about it with the conclusion "strongly recommended".
https://www.gestion-de-taches.com/tests-logiciels/test-blue/