Boston payments startup Loop on Wednesday has released its interesting take on the digital wallet to consumers, selling a programmable fob and a charge case on its website and launching its payments app in the iTunes App Store.

Loop’s technology is similar to that of Coin, which has been attracting a lot more attention to its forthcoming universal credit card. Both technologies offer hardware that will emulate the magnetic strip on any credit, debit or loyalty card. The main difference is that Coin has built what amounts to an electronic card you can swipe at any terminal, while Loop’s fob is contactless, generating a magnetic field that any point-of-sale terminal can read when within a few inches.

I had the chance to test out Loop’s $39 fob this week. The fob, about the size of a box of Tic Tacs, plugged into my iPhone(s aapl) — Loop says…