Developing coin software for smartphones would no doubt be useful but at the pace of adoption I think one might as well skip straight to tablets as the increased area make browsing a collection much less cumbersome. Still, one could design it to work across a variety of platforms to suit everyone. A simple app approach would integrate an online coin software site to allow for offsite viewing and remote adding of photos and notes. This isn't very challenging. For example, on tantaluscoins.com you can post your collection one coin at a time and at the point you're ready simply create an export which downloads an entire mini-website to your computer. All this with zero coding skills from the user. You can then upload it to your device and have access to your coins. However, without a dedicated app this limits you to interacting one-way as you can't add or modify the content "on the fly". If the main purpose is to look up coin values the main challenge is in keeping the database current with frequent updates. For the size of the potential market it sounds like a pretty risky investment. Aren't there sites that provide this info for free already? Ras