tus.io, in their own words:
People share more and more photos and videos every day. Mobile networks remain fragile however. Platform APIs are a mess and every project builds its own file uploader. There are a thousand one week projects that barely work, when all we need is one real project. One project done right.
We are going to do this right. We aim to solve the problem of unreliable file uploads once and for all. tus is a new open protocol for resumable uploads built on HTTP. It offers simple, cheap and reusable stacks for clients and servers. It supports any language, any platform and any network.