If you want to cultivate a daily reading habit, BookSlice is a good option. It employs gamification strategies like habit stacking and goal setting to get you into a reading routine. The service is built into Telegram so you can set personal reminders, track daily challenges and see streaks to monitor progress. It also uses AI to offer in-context answers to questions about the books you're reading. It's free for a month then $2 a month after that, so it's pretty cheap.
Another good option is Audioread, an AI-powered text-to-speech conversion service. This service converts written documents into spoken words, so you can do other things while listening to articles, PDFs, and other documents. It supports ultra-realistic voices and works on the web, browser extensions, iOS and Android. Audioread also generates a private podcast RSS feed so you can listen to your own content in your favorite podcast apps. The $9.99 monthly subscription gets you 100,000 words per conversion, 500,000 words per day and support for 77 languages.
If you want to remember and use your digital highlights from different sources, Readwise is a good option. It uses the spaced repetition technique to send you daily email reminders of your best highlights, helping you remember them over time. The service synchronizes and organizes your highlights from Kindle, Instapaper and iBooks, and integrates with note-taking apps like Evernote, Notion and Roam. With Readwise, you can tag, note and search your highlights, and it offers a 30-day free trial with pricing starting at $5.59 per month.