Instapaper is a mobile and tablet application that allows users to save and store articles for offline reading. It provides a clean and uncluttered reading experience by stripping away the full-sized layout of web pages and optimizing them for tablet and phone screens. The app's core features include a distraction-free reading environment, offline availability, and the ability to save most web pages as text only.

In addition to its core features, Instapaper for Android offers an optimized tablet interface, adjustable fonts, text sizes, line spacing, and margins, as well as dark mode and brightness control for night reading. Users can sort their list of unread items by popularity, date, article length, and shuffle, and organize them into folders. The app also allows for sharing via web browser and any app that supports sharing, rotation lock, and the ability to download up to 500 articles on a phone or tablet, with unlimited storage on the Instapaper website.

Other features of Instapaper include dictionary and Wikipedia lookups, tilt scrolling, page-flipping, preview links in the built-in browser without leaving the app, and search via in-app purchase. With Instapaper, users can read their saved articles offline, even on airplanes, subways, or Wi-Fi-only devices away from internet connections. The app provides a convenient and efficient way to save and store articles for reading anytime, anywhere.

Overall, Instapaper is a useful tool for those who want to read articles offline and on-the-go. Its core features and additional functionalities make it a versatile and customizable app for users who want a clean and uncluttered reading experience. With Instapaper, users can save time and stay informed by easily accessing their saved articles whenever and wherever they want.