I can't answer as to whether they're rogues (I'm certainly not going to download one to find out!), but given that mobile antivirus programs are a relatively new area, I would only trust one from one of the major antivirus vendors, especially since many of those are still beta versions. ESET, the makers of NOD32, just released their beta version, for example. Mobile antivirus programs don't work exactly the same way as PC antivirus programs; they really primarily on heuristics to identify potential threats, whereas a regular PC antivirus can use a combination of definitions to identify known threats, and heuristics to identify potential threats. The major vendors would most likely have much better heuristic models than some other company that is looking to just create mobile apps.
By the way, mobile9.com is a legitimate website that contains many free games and software for various models of mobile phones , but it is also a good source of mobile malware.I have got infected many times in the past before.
I would argue that any site that allows any infected downloads at all is not truly legitimate, and not to be trusted ever. A legitimate site would ensure that all of the apps available are malware free and trustworthy. If I were you, I would think twice about continuing to use it. I would only need to be infected once in order to stop using it. Why are you continuing to do so? You're putting your private data, and possibly the private data of your contacts, at risk by doing so.