Walaaxy is done by a team who know his job. They previously launched prospectin which also was a great product (that i used). Walaaxy is even better and i was surprised to see them on appsumo. It is really a good alternative to lemlist (almost for the linkedin part) and cherry on the cake they are from the same city than me : Montpellier (South of France).
I greatly recommend if you want to do lead gen via linkedin