I am assuming you are doing this for SERPs.
In order to answer that question, one must look at the source code which does not seem to be available here. I answered a similar question just the other day.
Besides two simple errors, the primary reason was nesting and compatible elements. Start with the simple - just the rating. Make that work. Then create the SoftwareApplication code separate from the other. Test it. Then nest the rating code into the SoftwareApplication code.
Here are some things you want to know.
BTW- The Google Rich Snippets Tool sometimes does not report an error when there is one. I have found this if you simply adjust the HTML code a bit. Frustrating.
Advice: When using the Google Rich Snippets Tool, use a complete but stripped down HTML page. Without it, you may not see the results you are looking for. I basically used a blank(ish) page and adjusted the rich snippet code with each test. Of course it took me time to figure this out. (Grrrrr...) Find something that works? Remove the HTML page and leave only the rich snippets code and you get nothing. Frustrating.
It is likely that at one point you very nearly had it or may have had it but a small error stopped it from working.
This is something that simply takes time to work out. The Rich Snippets Tool can be somewhat deceiving because your specification may be correct, but a simple HTML error could prevent the whole thing from working. It is not very forgiving. As well there can be an error that the Rich Snippets Tool is not reporting that under a different condition it would report.
Again, create a blank but simple and correct HTML page and just add the rating code till it works. Then remove the rating code and make sure your other code works as you would like. Then add the correct rating code into your other code and test to make sure you are nesting it correctly.
You already mentioned SEOSkeptic. I used this http://www.seoskeptic.com/count-vs-votes-error-for-schema-org-aggregaterating/ page which may be the page you were looking at. It is the best small example I have seen. Stick with it.