Reading pdf’s on small screen is a pain. For true pdf files is there any app that only reflows the article/text block that I click and not the whole page. Actually its a news magazine with varying columns between pages.
Thanks for your time.
To zoom and shift the page/text is not sufficient for you?
I like Chaka Book Reader.
Chaka is what I’m actually using. The dev is reachable on telegram too and they do listen. In fact, lots of changes have been added as per my liking.
Text reflow OTOH might need a massive rewrite of code I guess, thus increasing the size of the app. Hence, never mentioned it to them. I wish magazines were epubs (which are easier on my eyes) and not PDF.. haha
Chaka & Homer Audio Player for Seniors | F-Droid - Free and Open Source Android App Repository have helped me turn a disused phone into a book reader 
The deprecated (and archived) version of muPdf had this function. Now the app that does it is KOreader.
Librera has reflow too, not sure on columns…
KO’s ui seemed Greek to me. Tried couple of others too. And text gets jumbled. Sometimes lines take only half the screen space, leaving the other half empty.
And librera’s smart reflow gives me blank pages..
How about MJ PDF?
It doesn’t call the functionality reflow, but has a text mode that makes it easy to read documents.
For such heavy PDFs (Newspapers/Magazines) Free zoom in-out is best. You won’t get best experience with reflow view, articles will always look ugly and sometimes jumbled up + heavy CPU usage.
For such daily Newspapers I’m using MuPDF viewer. Librera also works but as per my testing it’s bit slow to load when you quickly zoom in-out. Librera is good choice because it has option to change PDF background - good for eyes.
Currently KOReader doesn’t support FreeZoom mode.
Took me literal years to get adjusted to it but I’ve recently settled quite comfortably with KOReader, I’ve found that it’s the only reader that makes reading .pdf files somewhat pleasurable on this one phone I have.
With MJ screen is half empty. Guess I have to go with zoom in/out. Thanks for the replies everyone.
This KOReader user plugin now supports FreeZoom: User patch request: Free Zoom · Issue #26 · Euphoriyy/KOReader.patches · GitHub
If anyone interested do test and report there.