Texpad on OS X is _scriptable_. That is to say you can add other programs that do clever but non-standard things to Texpad in a way that it let's them fit into its workflow.
_.tpbuild_ scripts are examples of such utilities. Their use is described in section 2.3.3 of Texpad Guide, accessible from the Help menu in the app or downloadable here.
Out-of-the-box, Texpad comes with a number of these scripts. More of these scripts can be downloaded from our TexpadKB repository:
https://github.com/vallettaventures/TexpadKB/tree/master/tpbuild-scripts
Some of these scripts were suggested and written by users to share with other Texpad users. If you don't find a script you're looking for here, please be in touch with us at support@vallettaventures.com.