First off, I want to apologize for any problems you're experiencing with the app. I know how frustrating this must be! Your suspicion is correct. It sounds like the trouble you are having is due to conference calling not being enabled on the phone. Allow me to explain.
TapeACall works by creating a conference call between you, the person you want to record, and our access number that records the call. To be able to create this conference call, your mobile carrier must support 3-way calling and your plan must have this feature enabled. Without 3-way calling, TapeACall will unfortunately not work.
If your iPhone does not successfully create a conference when you press the “merge calls” button, this likely means that you need to enable this feature with your carrier. Though most carriers do support 3-way conference calling, there are some exceptions, as we mention in our App Store description. It does appear that Virgin Mobile offers conference calling on some of their plans. Perhaps one of their representatives will be able to reply as well so that we can find out for sure if the feature is currently available on your phone. If not, you would certainly be able to find out by calling into their support line: 1-888-322-1122.
Thank you so much for downloading TapeACall. We truly appreciate every single user around the world and we hope we were able to help you get 3-way conference calling enabled on your phone. If there's anything else I can do to help or provide you with better support, please don't hesitate to contact me and the rest of our team! You can email us at firstname.lastname@example.org to ask any other questions you may have about the app. Thanks again!
An odd way to advertise an app by saying it doesn't work. I didn't know about the other apps you mention; this one was recommended to me on a professional mailing list, which is why I tried it first (and, to be fair, if I remember rightly, it's the Lite version that gets the low star rating, not the main app). I'll check out what else is available as you recommend.