Did you know there is a smartphone app for help in finding a lost pet? There was a news story about it tonight but I missed the name of the thing. Sounds good though.
There are come arguments against chipping on health grounds - Dogs suffer cancer after ID chipping If I had a choice I would tattoo my dogs, but as they are all rescues, they are chipped automatically and I have no say in the matter. Sorry to stray away from the orginal post - but I have no idea about apps, sorry.