It's 100% safe. The source code is readable, so feel free to view it.
Google removed APK Downloader from their store (they said it against the ToS), so I decided to removed Appstore APK Downloader too.
You can't download incompatible apps or paid apps, even you own it. Also currently you cannot download exclusive apps for Kindle devices :(
- Fixed: "Download APK" button didn't appear for some users
- First beta version
If you have any questions, feel free to contact me.