This is the link if you need more help understanding—-> http://threeacts.mrmeyer.com/25billionapps/

At 6:27 there  were about 507,655  down loads but at 6:28 there were about 541,892 downloads. So I subtracted the time which were 6:27 and 6:28 and got 34,237. I then subtracted 6:29  and 6:30 and  got  34,203. The average would be 34,213 downloads each minute.  So on February 24th at 6:27 p.m. there were 24,658,507,655  downloads. I subtracted it from 25,000,000,000 and got 341,492,345 more downloads left. So i would say at about  6-7 more days there will be 25 billion downloads.