You do not need a special tool, help from a neighbour or a hammer to open a pickle jar (or jam jar etc.). Here is the easy, no cost, no fuss method!
After being told of yet another 'special jar opening device' I realised that the time had come to let the world into a little secret: Opening jars is very easy indeed.
First off, why is it hard? When a jar is new from the shop it is hard top open. Once opened it is then easy to re-open. This is not because some machine at the factory screwed the lid of really well; no, the reason is air pressure. The jar has a near vacuum inside it when newly filled. This means the air pressure outside the jar presses down on the lid but there is no air inside the lid to press back up. This is like a huge vice clamping the jar shut! Once air has found its way into the jar, the pressure inside counteracts the pressure outside and the lid is then easy to unscrew.
Simply take a blunt (non carbon steal) knife, or a fork, and leaver up the edge of the jar a tiny bit. Not enough to permanently bend the metal of the lid, but enough so that you hear the 'woosh' of air going into the jar. This simple, no effort, act makes taking the lid off no trouble at all! There is no need to use a special tool or ask the local body builder around for dinner...
Once the air has filled up the inside of the jar, internal air pressure equalises the external air pressure taking the pressure off you!