In the A5E Tools Psion it lists Psionic Specialty, consistent with what is in the A5E SRD for chapter 2 of the Voidrunner's Codex. I believe this is what is listed as Mental Discipline (1) and (2) on the Psion class level table.
However, in the A5E Tools Psyknight it also lists Psionic Specialty, which is not in the SRD, and I presume a cut-and-paste error from Psion.
In the drop down menus, the destination for the Rules - Spells - Druid, brings you to the spell list filtered for Clerics instead of Druids as intended. All the other class spell list links from Rules - Spells - Classname work correctly.