What is the best reading app for seniors and large-print readers?

Text size matters more than any app feature, and the size of the screen sets the limit. On a phone, very large text means turning the page every few lines. A tablet such as an iPad shows a comfortable page at large sizes, and a Kindle e-reader adds an e-ink screen that many readers find easier on the eyes in daylight.

• Phone: fine for audiobooks and short reading sessions; keep the text size moderate.
• Tablet: the best all-rounder for large print, and the same apps (Libby, Kindle, Apple Books) work on it.
• Kindle e-reader: Libby can send library ebooks to it for US libraries, so you get free books on an e-ink screen.

• Libby: in a book, tap the center of the screen, tap the reading settings icon and drag the Text scale slider.
• Kindle app: in a book, tap the center of the screen, then the Aa button, and choose a larger size, more spacing or a different page color. Save the result as a theme so every book opens the same way.
• cloudLibrary: its listing says you can select the font size, margins and background colors.
• iPhone or iPad, every app: Settings, then Display & Brightness, then Text Size makes the phone's own text larger, and Accessibility Reader shows any text full screen in your own font and colors.

For readers whose eyesight makes print hard to read even at large sizes, our page on reading apps for dyslexia and low vision covers read-aloud tools and the free US talking-book service.

Reading on a phone or tablet can cost nothing at all. Libby and Hoopla are free with a library card. The Kindle app, Apple Books and Kobo are free to install, and you pay only for books you buy. The costs that creep up are subscriptions: Audible Premium at $14.95 a month, Kindle+ at $11.99, or Everand at $11.99. If you sign up for a free trial, put a reminder on the calendar for the day before it ends.

Apple Books lets you share purchases with up to five family members through Family Sharing, which helps when one person in the family buys the books. See our price index for every plan.

• Ask the library. Most libraries will help you install Libby and sign in with your card; some run regular help sessions.
• Write down your library card number and PIN and keep them somewhere safe at home, not in the app.
• Turn on audio as a backup. Borrow the audiobook of the book you are reading, so you can listen when your eyes are tired and your place stays close.
• Keep one app per job. One app for borrowing, one for buying. Fewer apps means fewer passwords.
• Turn off notifications you do not need in the phone's settings, so the reading app does not interrupt you.

Every reading app here remembers your page. Remembering the story after a break is harder, especially with long novels. The free method is to reread the last few pages before your stopping point. For supported titles on iPhone, Magic Bookmark recaps the story up to the page you are on and lists who's who, in a paper book, an ebook or an audiobook; the first book is free, then it charges per book. Our page on getting back into a book compares the options.

Audiobooks are a comfortable alternative on days when your eyes are tired, and the same story can carry on in either format. Libby and Hoopla lend audiobooks free with a library card; Libby lets you slow a narrator down to 0.6x or speed up to 3.0x and has a sleep timer for bedtime listening. Audible and Libro.fm sell audiobooks if you want to keep them.

If you read a Kindle ebook and own its Audible narration, Read & Listen switches between the two at the same spot, and Immersion Reading highlights the words as the narrator reads. See how to read and listen at the same time.

Every app on the App Store shows a privacy label. Libby's lists only diagnostics as linked to you, one of the shortest labels among the reading apps we checked. Hoopla's lists contact info, user content, identifiers, usage data and coarse location. Free apps from the big stores need an account with that store.

Library apps never charge you to borrow. If a message asks for card details so you can keep reading a library book, do not reply; ask at the library instead.

A relative can help without taking over. With Apple Books Family Sharing, up to five family members can share purchases, so one person can buy a book and another can read it on their own device. Libby and the Kindle app sync your place across devices, so a family member can set things up on a tablet and you carry on reading on your phone.

If a grandchild is reading too, YOMU - Family Reading Habits, from the makers of Magic Bookmark, puts a profile for every family member on one device, adults included, with streaks and reading time. Tracking is free.