I use Stackby for several weeks and I am really happy with it. Good points: well arranged interface with well thought details (= very easy to use), stable (zero problems so far), fully delivering what is promised (I definitely recommend to watch the webinar video mentioned in the deal description, it answered all my questions I had before purchase). Sharing with others works fine too, just note that when one user edits a record (line), this record is locked for others until the editing person finishes. Great compatibility with browsers (I tried Safari, Firefox and various chromium-based ones). Nice prints thanks to built-in printing system (although I would be happy if it would be possible to select zoom - at the moment, you print everything at 100% and I don't see a way to print a large table on 1 paper).

I can think about 4 things I would like to see in future:

1. some kind of automated backup - it is nice to have everything in cloud, but even nicer is to have the data with you for case something goes wrong. There is already 1-click download of csv, so if there would be possible to set for each stack for example automatic periodical sending of actual csv export to particular e-mail address, it would be great. (And if there would be way to load the backup back to stacks, it would be even better, and a way how to be protected against unwanted changes).

2. this is another level of the previous one - make an application that would allow to work offline - the idea is, that with access to the server, it would work as usual (with data directly on the server), but it would keep an updated copy of all data in the computer. Then, if there would be no connection to the server during application startup (= no internet or server down for example), it would load the last downloaded data and let work with that. I understand it would bring problems like synchronization and multiversion solving, but the offline mode would be awesome even with read-only access (no modifications in offline mode = no need to solve synchronization etc.). In short, the application would keep last version of data in your computer, and if the server would not be accessible during the application startup, you would be able to at least browse (and except adding/modifying/deleting, fully use in all other ways) your latest version.

3. you can create a form and generate a code so you can put the form onto your website. It would be nice to be able to do this with data - for example click Share, select Data share, select columns, filter and how many rows should be shown at once, and then get a code, that if placed on your website would show there box with read-only data loaded live from your stacks...

4. add scripting system, scriptable buttons, and freely designable layouts, improve user management - and boom - you have Access or FileMaker killer, that could work as a rapid development platform too.