Android/iOS ePub reader

We have a project on both Android: What we are looking for is quite a simple epub reader that would allow teachers ito download teaching handbooks and resources to read - normally without paying a fee, so we don't want a complex itunes paid-for store model. They would be able to download epub files from our own server and keep a bookshelf on the phone of training manuals they can refer to. We are also looking at iOS and Symbian app as well. Please let me know if you are interested and I will send you more details. Thanks