I have made an Android app for scanning Bitcoin and other cryptocurrency address QR codes and showing their funds. I would love to receive some feedback on the app functionality and feature requests. You can download the app for free on the PlayStore
https://play.google.com/store/apps/details?id=com.walletwatcher .
If you are wondering what the use case for this app is:
When I started with Bitcoin I held my BTC and other crypto on a paper wallet. Since you shouldn't store your paper wallet on your PC, I needed a way to easily scan the address and view the funds, without having to import the Private Key itself, since this would compromise the security of the wallet. So I developed an app to do just that. You can scan your address with your camera and instantly see the funds in BTC, USD and EUR.
I have bought a ledger now and with the app I don't have to connect the ledger to my PC to see the funds, which also saves a lot of time.
A second use case is for all the curious people out there. If you happen to see a crypto QR code somewhere outside and wonder much money there is on that address, you can quickly scan the QR code and find out.