If you buy an app,you can download the app for 10 times regardless which device you use.After you use up all your quota then you need to buy again.If for some reason you need to buy again then lodge official complain with nokia store or ask for refund.
Not once did I download the app after the time when I installed it. I had it in my profile/downloads for some days, but when Google HD Browser disappeared from the store, so did also the App from my downloads. From what I understand, the same has happened to others that have purchased either the Facebook HD Browser or the Google HD Browser.
I asked koonooz again about the disappearance of these apps, and from what I understand is that he did not get any information about them disappearing, he just noticed it himself and tried to contact Nokia about that but has not received any reply.
My guess is that what has been removed, stays removed and any complain in the matter (as a Nokia customer) is in vain; they will not bother to reply concerning something that has been ended (and with this I mean anything Symbian).