I have looked around to find a simple teleporter mod but to no avail, so I thought I'd make a request. All it would do is add a block to the game that when right clicked brings up a GUI that lets you change the frequency. Only two teleporters can have the same frequency, and once two are set to the same frequency all the player has to do is right-click the block and it would send them to the top of the corresponding teleporter. Maybe when you set a frequency it could change the color of the block or something to show which is which in case you have a lineup of them, and the recipe could use enderpearls or something. I can make textures and models if needed, I just can't code (I'm learning though, but its hard work without my own internet).
Just a Simple Teleporter