The exact evaluation of queries over RDF data has been extensively studied. However, in a wide array of applications, RDF queries do not even terminate, due to performance reasons. To address this, in this demonstration, we present PING, a novel system built on top of Spark, which allows to progressively answer RDF queries. PING first builds a hierarchical schema structure, which is used for effective data partitioning, sub-partitioning, and indexing. Then, it employs a novel RDF query evaluation algorithm that directly locates the different levels of the hierarchy required for query answering. This also enables answering queries progressively, by sequentially visiting the various hierarchy levels. The demonstration explains the novelty of our system and shows its effectiveness and the efficiency, on both exact and progressive query answering (PQA).