@Jessica Lares : I have in mind to use
this service to provide the Send to Kindle Service.
For Kindle Fire (based an Android) we now have our app in their store. Developing an app for reading-only Kindle devices doesn't seems easy.
About the RSS feed being slow, this depends on the server wallabag is installed on. It may be slow because all images are downloaded (even though a bug doesn't make them show right now if you use the official app). Of course, the more you have articles, the more it will be slow to load, so I advise you to use the RSS feeds for categories and tags if you can use them to fit your needs.
We have started again to work on an API for wallabag, and then we will be able to download a batch of articles at a time in the app, it should work better.
@exachillus : It is possible to export as epub more than one article at once :
* from a tag (see at the bottom of a tag page)
* from a category
* from a search
* all of your articles (see in config section)
Thank you for your returns.