Spectrum - Browser-based app to visualize the frequencies of an audio file.
Universal Dapp Store - Discover decentralized apps on ETH, Blockstack, IPFS & more
Roomvine - Chatrooms for real life venues, neighborhoods and events
DappRadar - A list of the best decentralised Ethereum applications
Treadie - Create your own micro-social network for topics
AppScope - Appscope, one of the leading directories for Progressive Web Apps (PWAs).