Impcat is an advanced
utility mod for Minecraft, it is based on ClientAPI
and includes a large number of useful mods
You can view a list of past and upcoming changes here.
If you donate $5 or more (and enter your Minecraft username), you will recieve a few small rewards such as premium mods, a cape visible to other Impcat users, a gold colored name in the Impcat Discord Server, and (eventually) access to closed betas of upcoming releases.
Please note that payments may take up to 72 hours to process.