I’ve done a lot of work updating Simple Spreadsheet for Material Design. My main impetus for this was because Samsung, LG, and a few other removed the 3-dot menu button from their version of Android, which was confusing a lot of people. In order to do this, I had to change the minimum android version (which was 1.6). Now, you require Android 4.4 to run the app. The vast majority of people are using 4.4 or later, so hopefully this won’t inconvenience too many people.
There are also many bug fixes in here from issues that people have reported to me. If you find more bugs (which is likely!) then email me or leave a message here.
Files are now located in the Documents folder on the sdcard. When the updated app first runs it will move any files and backup files it find in the old location to the new one. Anyone using something like FolderSync to backup their files to their Google Account should update their settings.
Currently all updates are only made to the Free version of the app. I will update the paid version in due course.