I just discovered an app that is hugely helpful to me. You may be interested too if you use more than one location for cloud storage. I am particularly guilty of this-- I have files stored in Dropbox, Evernote, Google Drive (two accounts) and Box. I actually like each of these services and the search functions work very well within each one. But too often I can't remember where I stored a particular file.
ClipCard has been developed for this purpose. After setting up an account it was easy for me to link all of the aforesaid storage sources to ClipCard. Now I can run a single search in ClipCard and it will scan all of cloud storage for hits.
The only drawback I have found to date is that the app is only available in OS. I haven't recommended an app in this space for a while, but this one could be quite valuable to others who have spread files throughout the cloud.