Slide Rule vs GoodReader Pro PDF Editor

This app is a slide rule simulator. The slide rule (a.k.a. slipstick) is an mechanical analog computer which was formerly used for various scientific calculations, engineering design and surveying. It consists of three linear strips and a sliding cursor and is used for multiplication, division, square, cube, square root, cubic root, trigonometry, logarithm and so on. Please note that trigonometry and logarithm are not supported and the width of the scale is 1,000 pixels in this version.

GoodReader® Pro and our famous classic GoodReader app are essentially the same app, but this one comes with Pro Pack® pre-activated, no subscription or in-app purchase needed. First released in 2009, GoodReader® is truly a veteran of the App Store. In the modern app business, it's not easy to stay relevant that long. We're proud to say that after 17 years and counting, we've been delivering wonderful updates with extraordinary new features. And we're going to keep doing that! GoodReader is a perfect combination of document-reading and file-managing capabilities. It's your one-stop shop for all your document needs on your iOS device. Use the app once, and you'll be hooked. Soon you'll be wondering how you ever managed to work without it. -= File Reading =- PDF, TXT, MS Office, iWork, HTML, pictures, music & audio-books, videos. This is what you can view in GoodReader, plus you can also annotate PDF files and edit TXT files. -= PDF Reading and Annotating =- PDF files is where GoodReader truly shines. Reading experience is so superior, it's hard to describe. To rephrase one of our customers' review, "try it, and you'll see." While you're at it, give our PDF Reflow feature a try. You'll be surprised how much better PDF reading goes when you don't have to scroll left/right all the time, for every single line of text. Annotating PDFs is another star feature of our app. Adding notes and drawings, highlighting text, and then sharing your annotated files or annotation summaries will be your main productivity and collaboration asset. -= File Management =- While reading files is a big part of GoodReader, it's not all it can do. It can also serve as a central hub for all your files, even those that can't be opened by GoodReader itself. It's like bringing your personal computer experience to your mobile device — easily managing huge collections of files and folders will make you forget you don't have your laptop around. -= Connecting =- Dropbox, OneDrive, Google Drive, Box.com, WebDAV, SMB, FTP, SFTP — these are all accessible from inside GoodReader. Download, upload, and sync individual files or huge folder collections. -= Security =- With GoodReader, your data security steps up to the level previously only dreamt of. With Pro Pack®, our new set of professional-level super-features, you'll get AES-256, a military-grade encryption, for all your data, at a price of a cup of coffee! And it's completely independent from the built-in Apple's Data Protection, so even if a hacker steals and unlocks your device, your data will still be protected by another strong layer of security, our own. -= Multi-Windows =- Seamlessly view and manage multiple files simultaneously on iPad. -= Notes =- Capture ideas and comments while reading or studying a technical document without even leaving the app. Sort and group your notes into categories.