<<cough>> just a gentle plug for this:http://www.bookcrossing.com/---/546644
My view on the topic of this thread is that donations can be made to the site at any time by purchases from the store as well as membership/wings, and also via the "donate" button at the bottom of every page on this site.
Perhaps rather than a Crowdfunding appeal, it might be worth BookCrossing HQ to call for XX amount of money to be raised through 2018, in order for a mobile friendly/app to be funded. >>Note that I have never personally seen BC HQ acknowledge that they are willing and / or are able to look at investing in the development of an app.<<
That said, I've been a member of BookCrossing for years, and will admit that I have no idea how much it costs to run the site, and also how close we sail to losing the site altogether on a month by month/annual basis.
Not saying that info isn't out there...just that I haven't seen it.
For all we know, there could be a whole bunch of funding needed to the general running of the site before we can even think about an app.
I'm gonna "go there" tashclayton and say that your lack of wings highlights that you aren't ticking the very basic method of supporting this site, and therefore <if I were the powers that be of BC>I'd be less inclined to be receptive of your call for "more" so to speak.