Yay, software IP! A world of fun! Chances are nobody will mess with you for just writing the program, but associating it with a for-profit commercial product is asking for a cease-and-desist at least. It looks like the patent expires in January 2022, but for the moment, it’s owned by a patent troll firm. That’s um, not good. (google “wsou investments troll”)
---- STOP HERE TO DODGE SOFTWARE IP LAW TL;DR –
(Speaking as someone who patented a pile of things for a major corporation: (1) software patent law is deeply annoying and silly, and desperately needs reform, (2) the big guys take protecting their IP really, really seriously, and (3) patent trolling is a huge problem for everybody.
The big companies may seem like malevolent jerks, but what they’re actually doing is protecting themselves from each other – if Apple lets a little infringement slide by just once, Samsung can and will nuke them with that fact in court, and then Apple may lose incredibly profitable rights to something they invented. Shareholders pretty much insist that companies protect those rights.
It’s a very, very expensive game to play – terrible for smaller players. And patent troll companies, who buy up patents and use them to sue everybody in sight, big or small, make it even worse. Best to avoid poking lawyers when possible.)