Searching for replacements for some Synology apps (photo and music)

I’m having a Synology NAS and I really like this device. There is only a single backside: It uses proprietary stuff. So I installed Owncloud a long time before and now upgraded to Nextcloud.

Concerning the file sync I don’t see huge differences between Synology and Nextcloud. Nextcloud is a step ahead here, since with the Synology sync I can only sync a single folder. But I’m doing much more with the NAS than just syncing files. Especially I’m using two applications that I would like to have replaced with Nextcloud apps:

  1. Photo: Synology provides the Android App “DS Photo” which not only can be used to upload taken pictures (yes, I know, the Nextcloud app can do so as well) but also this app can be used to browse easily through the albums. Additionally the web based photo app “Photo Station” is looking good. Here is some german article about it: Synology Photo Station: Es muss nicht immer Cloud sein

  2. Audio: The audio station is a good usable and good looking audio player:

    The android app “DS audio” is a usable audio player that is linked with this player so that they share the playlists. Music can be stored offline on the phone, etc.

In difference to the Synology web applications the Nextcloud apps seem to behave sluggish and they don’t seem to have much features.

So my questions are split in two parts:

  1. Are there Android based apps that provide a photo album and a music player that are connected to Nextcloud with offline abilities?
  2. Are there more advanced photo and audio web applications out there than the standard ones?