Texpad for OS X is available directly from us

https://www.texpadapp.com/osx

or from the Mac App Store

http://itunes.apple.com/app/texpad-latex-editor/id458866234

Limitations of the App Store version

Since OS X Lion (10.7), Mac OS has had the ability to "sandbox" applications - a restrictive security model for applications, that has worked well on iOS, but which is incompatible with traditional distrbutions of TeX, such as TeXLive, MikTeX, kerTeX and MacTeX. When developing the iOS app, we adapted TeX to create our own vvtex typesetter that is compatible with sandboxing, and has been running well for some years now.

We cannot write a sandboxed version of Texpad that works with traditional TeX distributions, and Apple is beginning a phased removal of unsandboxed applications from the App Store, so we will be switching the App Store version to use the vvtex typesetter only

Texpad will continue to be distributed both inside the App Store and via texpadapp.com and the website version of Texpad will will continue to support external TeX distributions such as TeXLive and MacTeX in addition to our own vvtex typesetter.

You will at any point be able to switch from the Mac App Store distribution stream to the texpadapp.com distribution stream, but it is not possible to go in the other direction

Texpad outside the app store

If you wish to continue using a traditional TeX distribution (and we expect that most of our customers will) then please migrate your Mac App Store copy of Texpad as described here, or buy it directly from us.

Texpad inside the app store

Mac App Store Texpad is being sandboxed properly in the way that our iOS version of Texpad is, when finished it will use the same typesetting engine (vvtex) and bundle manager that is built into Texpad iOS.

When we are finished with this we will update the Mac App Store version and from that point, both MAS Texpad and texpadapp.com Texpad will be updated simultaneously. This is near completion now, and it will happen with Texpad 1.7 towards the end of 2014