To use:
first make a obsidian frame like so:

To go to nyanland:
Grab a nyanland mese activator and rightclick the empty obsidian portal you just made. Jump in, wait and you will get to nyanland.
To go to the nether:
Same as nyanland, only use a nether activator.
To use a teleport portal: (Very useful in mines)
Grab a teleport mese activator, rightclick where you want a new portal, and rightclick on a built portal.
CREDITS:
most of the code is from PilzAdam's nether mod.
DOWNLOADS:
github repo
download
NOTE: do not try using the nyanland portal if you do not have the nyanland mod
DEPENDS:
default
License (code and textures):
Attribution-ShareAlike 3.0 Unported (CC BY-SA 3.0)
more in readme.md