What are some special meditation techniques and/or objects that have been used to develop mental abilities to the point of almost being super powers or super human? Not necessarily "super-mundane" as ESP but something along those lines. There is a lot of controversy in searches but I can not find any specific references. I could read the suttas myself but I am looking for direct tipitika, Buddha involvement.
In ancient India (mostly in southern parts of India) there are people called "Sittars". They possess many super-human powers like foreseeing the future (not just predicting it), alchemism (like converting any metal to gold), super-healing abilities. There are many written manuscripts which are still available but many of them of in Ancient Tamil. They have also written about many techniques which if practiced properly will give us super-human abilities. Do not think of "Wolverine"-like abilities, but the sort of abilities that normal people cannot think of. It is rumored that they still exist in the western ghats of southern India and that they are in a form of light. I do not know how it is linked to Buddha but I firmly believe Buddhism has its core roots and values derived from Hinduism.
One of the teachings of my own tradition is the use of inner imagery after overcoming bias. Our inner accuracy improves once we learn to identify what is biased and what is not, and this could be called 'clairvoyance' by most, though this doesn't necessarily mean you are seeing what is there.
It is also said that siddhi meditations develop human superpowers, as well. But in the case of siddhi, there is a lot of esoteric learning that has to happen first, some of which is lost to time.
Most Masters won't speak or initiate student directly. This kind of abilities come naturally along the way, as fruits. The Master will only help the dedicated student growing up, and once some vibratory path are achieved, the Master might on a subtile way guide his student with this kind of new abilities.
So, in the tradition, this happen naturally behind the scene and there probably no practice nor techniques that exist.
Further more, focusing on this kind of goal might be a tricky path, since the only aim is to recognize the Absolute True Nature within yourself and everything around.