Creating an app for audio sermons

Hello everyone, we are a small church and we are looking to have someone develop an Android/iOS app for us where our audience will be able to have easily access to our audio sermons. We have a currently existing website, with an identity of its own, but the audios there are not as easily accessible as we would wish, as the website is somewhat lagging. We would love the developer to design and build the app, to some extent following the concept of Audioverse (an app which allows pretty much for what we are looking to offer our friends online). We have approximately 50gb worth of audios. Things we would look for: - A vectorized logo fully inspired from the already existing background image on our website - A page for each sermon, where users can listen, share on social media, and also download the audio on their phone. - Several categories, such as: sermons, series, conferences. - Possibly (if that does not require too much work), an automatic encryption of the audios (like on Soundcloud) making the listening easier for those who have slow connections and/or cheap phone plans. - An interface for us whereby we might regularly add new audios, series, and conferences as time goes by, without the help of a developer. And much patience, for we are not savvy with this whole thing of app development. Thank you for your inputs. Please note that, we are essentially looking for a quote to get an idea of how much this would cost us, but won't be able to hire for now.