I would have found this article to be so much more useful if it had included one little four-letter word:
What ***SAFE*** Alternatives Are There to the Google Play Store?
With the rise of malware-injecting apps directed at the android platform, and with warnings regarding how one should be careful when downloading apps from third-party providers - it would be very helpful if the safety factor had been included as an element in this article.
Having said that - I have no doubt the author of the article is an experienced expert. However, for those less experienced (such as myself) it leaves one with the idea that it's safe to go to any of the sites mentioned and download any apps with worrying.
I'll still check out the sites because I'm very interested in alternatives to Google Play - but how careful do I need to be ?