So you're spending all of this time to make an app that uses and relies on the DP database and the only way to submit a correction is to go to a PC, log in to DP, post on a forum, and hope that one of the database maintainers fixes it. Instead of using the application that's already in their hand...
Since you're asking for donations to purchase a new PC, why not buy the Mac from that? You could do the Android and iOS versions from the same system, and not require the purchase of an additional PC.
How is this volunteering? You're being paid up front, and after the application is delivered. You're asking everyone else to take the risk. We have to trust that after paying you $4,600, you'll produce an app. It seems a reasonable risk, but the risk is on us, not you. Take a look at sourceforge for all the applications that started with good intentions, but were never completed.
Maybe i wasn't clear. I'm not claiming you're charging any individual twice, but the community as a whole. Your only real audience for this app is the DP community, which is the same community you're asking for donations from. On that note, how exactly will you be giving the free copies of the iOS version to the people who donate? As Skaar said, you have a limited number of free codes for a published iOS app.
This is just rude and disingenuous.
Yes, as any long time and active member of the community should be able to tell you...
You're asking for DP members to pay all of your upfront costs, including the hardware and worker's time. It seems improper to use that as a justification for the cost of the app as well...