If you go looking for Koush's Vysor today, you won't be able to find it. Koush has announced that he had to pull the screen sharing app because of codec licensing. Despite being more or less ubiquitous, the H.264 codec isn't a free standard. Koush was contacted by MPEG-LA and told he'd need to license the decoder in Vysor for $0.20 per user. Koush opted to pull the tool from the Chrome web store instead, but he's on the hook for previous downloads.

At issue is the broadway.js decoder in Vysor that gets the video of your phone screen onto other devices. It's essentially a JavaScript-translated version of the H.264 decoder from Android. MPEG-LA is the consortium that owns the patents covering H.264, and it has a famously murky set of rules about who has to pay and how much. Most small devs aren't probably going to get a knock at the door, but some will. According to MPEG-LA, you get 100,000 free licenses, but it's $0.20 each after that for up to 5 million. Then it drops to $0.10 each.

Vysor is free to download, and at $0.20 per user, that could mean a big bill for the codec. As it stands, he's still being asked to pay for all the previous downloads—so, some non-trivial amount of money. Koush is looking into a solution, but switching codecs might not be an option. Unfortunately, H.264 is supported on all devices, whereas the open VP8/9 is only supported on some. It's possible Vysor will come back as a paid download, but Koush isn't saying yet.