Handy Tool.. But...
IPv4 in my opinion works well.. with the binary and integer representation option being a nice plus.. The IPv6 (which you have to pay $1.99 to unlock) technically works. The precise full representation of all 8 hextet groupings for the given address space works with the subnet slider. You can shortcut compress the trailing zero’s or else the start and end addresses represented displayed will be way off.. I had higher hopes for the IPv6 aspect of this app.. that was really the entire reason why I bought it. My fingers are crossed that the next update to the app corrects this and adheres closer to how IPv6 addresses and address blocks are referenced and represented. Holding out hope because it really would be a handy subnet calc otherwise.