Two more Android apps from me, and they have a few things in common. Both work offline, neither wants an account, and you pay for them once instead of every month.
Paperline is a document scanner. I made it because every scanner I tried wanted a subscription or my email address before it would save one PDF of one invoice. You point the camera at a page, it finds the edges, flattens it, cleans up the shadows and reads the text, all on the phone. You get a searchable PDF. It also names scans from what's written on them, so you get a date and "Invoice" instead of "Scan 47". And it can put both sides of an ID card on one A4 page at real size.
Stash is read-it-later. I wanted a Pocket replacement that keeps everything on my phone. Share a link and Stash writes it down before it even touches the network, then downloads the whole article with images. Read it on a plane, highlight, tag, search, or let the phone read it out loud. Your old list from Pocket, Omnivore or Instapaper comes over in one go, and everything goes back out as Markdown whenever you want. There's no sync. That's the price of having no account and no server, and I'd rather say it upfront.
Same deal for both: 7 days with everything, then one payment. No subscription. If you don't buy, nothing gets locked away - your PDFs and saved articles stay readable and exportable.
Grab Paperline and Stash, and if they're useful to you, throw money at me.