Viz/Mangaplus only stream Shonen Jump titles. We are currently focused on the thousands of other titles that are out there that aren't getting that level of love. We are here to bridge that major gap so even more is available in English.
We are planning to add multi-select for the Genre filtering. Our backend supports it but haven't implemented the frontend portion yet.
Free chapter availability are currently limited by the original publisher's rights and we are working on that!
We're also working to add more series and have more coming soon. Adding each series takes time and money unfortunately.