As far as I am aware new lessons are put up every week. Therefore after next week there should be more lessons. I would encourage you to use other resources as this one is reletively new and if you've already finished the 26th lessons and your asking for more the webesite may not be at an advanced level to suite your needs. However it's always good to practice old materials and by the time you've refreshed it all I'm sure there will be more lessons out there for you :)
Yes, we try to add new lessons, drills and quizzes every week. Sometimes it takes two because we strive for high quality lessons that make sense. So, hang in there.
To continue learning beyond the lessons, I would suggest the study lists and custom drills. Premium members can add any word/kanji to their drills from the dictionary to accelerate their vocabulary growth. Personal and public study lists also make it easy to study towards certain goals. For example, there are JLPT based study lists for words/kanji under the dictionary. You can also make unique study lists and share them with the community.
Every week, we have community chat events where you can find pen pals that are at your level as well as communicate with our Japanese instructor to ask additional questions.
Hope that helps!