Question: I need a subscription service that offers a mobile app to read academic books on-the-go, with features like read-aloud and customizable speeds.

If you're looking for a subscription service that offers a mobile app for reading academic books on-the-go with features like read-aloud and customizable speeds, Perlego is an excellent choice. It offers access to more than a million professional and academic ebooks covering a wide range of subjects and offers a mobile app for reading anywhere. Perlego offers read-aloud technology with adjustable speeds, keyword search, note-taking, and a color-changing font to help you read faster. It also comes with an AI-powered research assistant and study guides written by experts, making it a great tool for students and independent learners.

Another option worth considering is NaturalReader, a full-featured text-to-speech tool that can handle a variety of formats including PDF and Word documents. It offers natural-sounding voices in more than 50 languages and offers features like voice cloning, content awareness, and assistive technology for people with dyslexia or ADHD. NaturalReader offers a range of voices through its web app, mobile app and Chrome extension, and you can download MP3 files for offline listening, making it a good option for educational use.

If you're looking for an AI-powered text-to-speech conversion tool, Audioread could be a good option. It lets you convert written documents into audio and offers multiplatform access through a web app, browser extensions and mobile apps. Audioread lets you convert text to audio from sources like emails, PDFs and articles, and it can create a private podcast RSS feed so you can listen with your favorite podcast apps. The service works in 77 languages and offers a subscription plan that lets you convert 100,000 words per conversion.

Last is Playtext, which takes a different approach by converting text into audiobooks with adjustable reading speeds. Playtext works in multiple languages, and you can listen and read at the same time for better comprehension and retention. The service is geared for students and professionals who want to get the most out of their reading, with unlimited listening, book uploads and research paper support for an annual subscription of $10.