3D Applications, like Blender, Maya, Modo etc. are as good as After Effects for mocking up things like this. Perhaps better in some regard, although typography is typically easier in After Effects. 2 dimensionality is after all just a subset of 3D. Slap in a orthographic camera and you are set
You may need to work on the workflow a bit upfront. So saving out some nice models of buttons and animation key frames/expressions will speed up your workflow for future projects too. But this applies to any software.
I used to do this a lot, though personally I avoid blender. But since I am not using any features that do not exist in blender same applies to blender, as it does to modo, Houdini and 3dsMAX
Image 1: Quick and dirty mockup of a possible mockup (10 min from scratch) done in Maya. I'm in a bit of hurry so no time to refine this. Works equally well in blender.
PS after effects is not a mac only app.