By the way, I haven't problem to download this plugin and e107 helper from e107.org. But I use latest 2.3.1 version.
Those github versions (both plugins) are newer and you need to manually download from github, unzip, rename (remove master from folder name) and copy to e107 plugins folder.
But if I remember correctly, last opinion of CaMeRon was that e107 Helper is too old and it is not worth saving.
Are you sure you want to use a solution from 2008 year?