Hey all! anyone know a good free ereader that has accessibility functions?

I have a kobo Clara color. Not sure if you can change the background color, but it has a "dark mode" that inverts the black on white, to white on black. You can also highlight in various colors, change font size, line spacing, margin, and it even comes with the "Open Dyslexic" font.

Edit: Derp, you said free... I can delete if you want :/

Thanks mate can't afford money ones

Which platform? There are good readers across the board.

Thanks mate it's android
- Sure, so I'm currently evaluating FOUR of them trying to determine which one I like best:
  
  eBoox, ReadEra, Moon+ Reader, and Librera.
  
  eBoox lets you change the page color, but the controls are a little buried and there are only 4 colors to pick from, white, beige, gray and black.
  
  Readera has more sensible controls and more page color options. Night and Sepia both have high contrast options where the text seems bolded.
  
  Libreara has even more page color controls than that, about 8 of them.
  
  Moon+ appears to have the greatest control allowing you to define colors through hex codes and apply your own background image. Pretty good font controls too.
  
  I haven't really decided yet which one I like best, right now I have a book open in Moon+ and Libreara and both function fine, I'd have a hard time picking one over the other.

Like, a software package or a hardware device? If software, for what platform?

If you mean a software package, on Linux, I use foliate in dark mode. It has somewhat-configurable color settings. I've also used calibre, which is for various desktop OSes and has more extensive configuration, but is also a rather larger package, intended to manage a library of ebooks as well, not just read one.

I don't know what you mean by "use a ruler". You mean that you need to place a ruler under the text because the text is so small? Like, are you asking for something that permits the text to be resized? Columns made narrower, so that it's easier to not lose which line you're on? Only show text a line at a time?

Thanks mate! I'm not good with tech I meant an reader for my tablet? I need more than dark mode I have to change it from white background to like an orange cos otherwise I can't read for long.

The ruler is a thick line move down the page as i read to help me focus on the page. Otherwise the writing can blur.
- Is this an Android tablet, do you know? Like, an Amazon Kindle or something?
  
  There are several different types of tablets; some, the ones from Apple, run iOS. Others run Android, like smartphones. And others run Windows. Different software packages for each.
  
  EDIT: It sounds like losing-place-in-text is a thing with dyslexia, so there is some software that has been designed around it, but can't really know what to use without knowing the platform that you're on.
  
  Like, this guy has some commercial website reader thing that talks about it:
  
  https://readermode.io/
  
  Probably not what you want, since you're looking for an ebook reader, but he talks about how having a highlighted line can avoid the problem and how some fonts can reduce the effect by have letter shapes that vary more, stuff like Comic Sans.
  
  This comment says that the Android app for Kindle reader software already has such a feature. I'm not sure if you're using the Kindle app or not, but if so, you might already have that feature:
  
  https://old.reddit.com/r/ereader/comments/18s3t65/highlight_function_for_reading/
  
  I just checked it on a Kindle Paperwhite + the Windows Desktop app and an Onyx Boox Nova Air 2 (and a Boox Boox Note Air 3 C, a Boox Tab X, and a Samsung Smartphone): On the Paperwhite + desktop app I could not find it, but on the devices which use the Android app for Kindle there is something called "reading ruler" that highlights the line you are currently on (I am German so maybe this is not the exact translation you'll find). To access this, you just open a book, tap in the middle of the screen to open up the menu, go to the "Aa" menu and there to "More", and there (sadly not on the Paperwhite) you find the "reading ruler" (Leselineal).
  
  This means you just need a device that runs the Kindle app for Android (Nova Air is on Android 11, NA3C has A12, Samsung has A13). Maybe your reader does that (I am not familiar with your Pocketbook, sorry).
- Just in case you can't find an electronic solution, I wanted to offer a mechanical solution of an inexpensive transparent film you could put over top of your screen to change the current white background color to one that is more compatible with your eyes for longer use. Something like this:
  
  source

PocketBook Reader lets you change the background color to whatever you want. You can also change the line spacing/font size/etc, and it's possible to add fonts as well, if you need something specific. It can be a little convoluted to make it do what you want, though, and there's not much documentation. (I'm happy enough with it, but YMMV.) Also, no automatic line highlighting that I can find.

KOReader supports custom CSS. You can certainly change the background colour with it, I think a grid should be possible too.