Yes, it is possible to compare two applications with SVN.
In the first step, you must import application A into a repository. For this you must use a SVN tool (TortoiseSVN, VisualSVN) and create a corresponding repository and then you must open the application with Machine Expert and import it into the previously created repository with Project-> Subversion-> Import Project to SVN ...
After importing Application A, you must open Application B with Machine Expert and you have two options how to compare the projects.
Option 1: You can compare Application B directly with a remote project (Project->Subversion->Compare to remote project ...). This function will show you the differences between Application A and B.
Option 2: You can connect Application B directly to an existing SVN project (Project->Subversion->Connect to existing project ...). This function will link Application B to the SVN repository. Afterwards you can see in the device tree all differences between the Application B and head revision (Application A) in the repository. Now you can check the differences between Application A and B step-by-step.