Kobo is launching a new monthly subscription service called Stack that lets you upload your own ebooks and documents to the company's servers where they'll be synced across multiple devices and apps, including your reading progress, highlights, and annotations. Kobo Stack is similar to Amazon's Send to Kindle feature that allows users to upload a wide variety of files to their Kindle libraries for free, but Kobo's version will cost a few dollars each month.
Kobo Stack is being introduced as part of a major 6.0 update to the company's e-reader software, which is available in beta now as an optional upgrade ahead of a wider official release. …
