CamScanner alternative? [Android]

Question

Recently CamScanner has become annoying with ads and popups. So looking for an alternative document scanner on Android, hopefully with these features:

1. Anti-shake (what I really liked on CamScanner: when you click, it won't take photo until phone becomes still, so reduces blurry images)

2. No ads.

3. Upload to Dropbox.
4. No monthly subscription (one-time purchase is okay).

Optional (nice to have):

5. It's own cloud sync (CamScanner has 400 MB free cloud sync). I find this useful because you can access your scans from the computer automatically (without uploading to Dropbox).

Thanks.