Yeah I'm not too happy about using apps to view cameras. I've already got an IP camera at home, didn't sign up for the cloud so no bank details, no address; all they have is email address and the app was through Google Play Store so has to meet their security protocol and there was no intrusive permissions asked for when installing it. Yeah they can probably access the camera feed in China and waste their server space storing video of a concrete driveway, no car regs visible or house numbers so doubt they could actually tell where it is as all they have is my IP address which only narrows it down to a city and even if they could I'm not sure how they could use it. I would never use one inside a house as some people do where they could see and hear personal stuff.
It's a calculated risk at the end of the day, they get some pretty useless data and I get a fairly cheap, easy to install camera for £200 or so. It's that versus paying high hundreds for a full dvr kit with multiple cameras that I don't really need and the massive faff of installing them, drilling holes in walls, running cables around the outside of the house and finding somewhere to put the dvr. Also if you haven't got cloud backup and you get burgled they can just take the dvr or smash it, at least with a stand alone camera mounted high up someone has to bring a long ladder to get to it which seems unlikely for the average burglar.