Proof of existence Alternatives

Proof of existence is described as 'Allows to certify a document ( of any format ? ), it gives a fingerprint relative to the date of the certification and it is stored in an online "Bitcoin blockchain"' and is an app in the Business & Commerce category. There are five alternatives to Proof of existence for a variety of platforms, including Mac, Windows, Linux, the Web and Android. The best alternative is Cesium, which is both free and Open Source. Other great apps like Proof of existence are ZeroID (Free, Open Source), Stampery (Free), OriginStamp.com (Free) and Woleet (Paid).