The iOS app catalogue and the current online ebook version are two completely different platforms and products; there's no overlap whatsoever.
There was a new iOS app that was basically just a wrapper for the website. I have it on my iPad right now, because I installed it in the beginning of January. I used to have the old and new app side by side, but the old app is still 32 bit, so Apple pulled it.
Right now, if I used the new app to login to Scott Online, I get a 503, Service Unavaialble error.
You are correct that the old app was indeed offline, because it was nothing more than the front end to a bunch of encrypted PDF files. In that respect, it was superior.
I think in 2019, stamp collectors don't need a catalog any more. They need a database, and they need real world values for stamps, so they came informed purchasing decisions.
The problem is that Amos Media abandoned it, and the app is no longer compatible with current versions of iOS. I have it installed on my iPad pro, as I had purchased a complete set of 2015 catalogs in it. The app will not run.
Amos created a whole separate company around their online offering call Amos Digital. I think their plan to was create an online catalog and then have other collectible catalog companies come to them, so they could make them an iOS app for a fee, and then have Amos Digital becomes a money maker for them. Well, no one came knocking, and they shut down that part of the business, taking the Scott Specialized Catalog I bought with it.
The new eBook version is a major step backwards in functionality, as it can only be used online and the pages are rasterized rather than being vector data, so you can only zoom in 1-2 magnification levels before the text becomes unreadable... a bit of an issue with a print publication that uses 6-8 point type size.
This is a huge sore point with me. I think the new Linn's Stamp News really got their online offering right. The catalogs are abysmal.
I read somewhere once that for the longest time the Scott Catalog was laid out by hand, even into the 2000s. Then they switched to, I believe Adobe FrameMaker, which is a DTP program specifically designed for huge books and technical documents. That's when the CD-ROMs came out. Because they could finally print to PDF.
I think what Amos really needs to do is offer watermarked PDFs, or if they really want some kind of DRM around their product, they could use Adobe Digital Editions.
There are existing solutions to their problems that does not involve raster scans of printed pages. In the mean time, I'll just keep buying from scottcataloguepages.com and scanning in the pages into PDF on my tablet.