iOS: You can store lists of your valuables in Evernote or Dropbox, but those platforms won't help you automatically value those items or remind you when to renew an insurance policy. If you want those kinds of features, My eVault is an Australian-developed app that helps track your most valuable assets.
Data can be entered into the app by typing, taking photos or dictating information through Siri. The app incorporates a separate passcode so that your data won't be accessible if you lose your phone. You can also generate reports if you need to make an insurance claim.
My eVault is available in a trial version which lets you track three assets, one insurance policy and two travel wallets. The full version costs $6.49.
My eVault [iTunes App Store]