Welcome, but if I may suggest -- before trying the app, get oriented on a regular computer browser, so you can see the logic behind the columns and can take advantage of some of the other features.
For instance, If you want to see posts in Japanese, you could search for #japanese, then pin the column that the search creates. All subsequent posts with that hashtag will appear there.
@AutoManipflanja
or you could even search for a common Japanese character that will appear in almost any text, the way English speakers looking for English posts in a Japanese forum might search for "e."