This mod has been merged into Forge itself! You no longer need it and it might even cause crashes! It will only stay up as a reference project for new modders.
By default, minecraft only supports up to 26 advancement tabs (8 on bottom and top, 5 on left and right). Bigger modpacks will easily hit the limit.
This clientside mod modifies the advancement screen and adds 2 buttons at the top to allow switching between multiple pages.
Disclaimer
This mod consists of 2 parts that are bundled into one jar. The biggest part is a coremod which is getting assisted by a really small FML mod. This means, the mod is currently not compliant to the Forge Coremod Policy! I will work on that as soon as possible, but at the moment, forge does not support loading coremods from embedded jars and I dont want to ship the coremod + a single classfile mod separately.
Modpack Permissions
Yes, you can use this mod in a modpack.