I had used the Gravity Twitter client for a while during the free test period and was seriously thinking of buying it which I did as my first buy on the E71. A couple a days ago the E71 developed a serious problem where I found out that the only way to remedy it was to reset the device by reinstalling the latest firmware (200.x.y in Sweden - where is the 210.x.y version with the improved camera software Nokia???). After I reinstalled the firmware I accessed the Ovi account on the E71 to re-download the Ovi App Store application, Gravity Twitter client and the Skyfire web browser. I couldn't!!! They where there under the headline "My Download History" but I couldn't re-download them. It says Installed, but the only way to get it back on the device is to actually buy it again. I tried to re-download the Ovi Store App, but the got an "Item unavailable" message. I like to be proven wrong here, but I googled around a bit on the problem and sadly, I found out that I wasn't alone.
In contrast I have four iPhones in my family, they are all using the same iTunes store account and I have downloaded some of the applications to more than one phone. No problem to do that. Reinstalled an iPhone - not a problem, just reinstall the applications and you are fine to go.
Sorry Nokia, until you enable the possibility to re-download any previous purchase made in the Ovi App Store, I won't buy, not even download any free app at all! If there is an application that I really like, I will contact the developer directly.
Until then, I'll stick with the iTunes app store!