Is the app an offline app? Ie, will it need a huge amount of storage on the mobile for all the pictures and data... and then go out of date quickly as new pins are released.
Or will it be online, meaning its useless without a network connection? Also means it requires constant server back-end/maintenance/ongoing costs.
Neither of those seem like good or feasible options, especially for a 'free' app.
Also, there are already efforts underway to unite the various (online) applications together. So for example pintips.net (which does the tips thing your app is suggesting) already links through to eg pinballvideos.com, which also both link up to pinballmap.com, and ipdb.com.
SO maybe your app is just a front screen that ties these resources together? I've been very tempted to do an app for that myself. But... lazy.