We are currently using Kafka Manager (https://github.com/yahoo/kafka-manager). It seems Kafka HQ have the same features (it is not clear from the doc if you can actually manage the partition arrangement or only view it) plus the possibility to view the actual messages that are streaming in Kafka that might be very useful.
View message inside Kafka was my main goal when building KafkaHQ !
Unfortunately, you can't, for now, reassign the partitions, but maybe I will can add the feature when this one will be ready : https://cwiki.apache.org/confluence/display/KAFKA/KIP-455%3A... (targeted for Kafka 2.4, but I don't think this was release)
You can only set the number of partitions when you create a topic in KafkaHQ, not after the fact. You can view messages, even if they are AVRO encoded and backed by a schema registry.
