It's always somewhat unsatisfying when there's no developer web site or 'about me' page - all we have is a Vietnamese developer/publisher name. Regardless, there are a couple of dozen applications, with some overlap. My main concern is that the sources of all the information (textual and graphical) aren't disclosed - whilst some may well be public domain, there's a nagging doubt that other data might need its source clarifying and crediting.
And from Disease Dictionary:
In fact, quite a few entries have 'no information'. It really would be very handy if the developer quoted his information sources in each of these apps!
And from iHealthy:
In short, the developer has done a decent job of packaging up a variety of medical sources in palatable form on Windows Phone. With Windows 10 imminent, here's hoping for 'universal' versions and also with proper accreditation where appropriate. For something as important as health, you can't seem to pluck data from thin air, you know...