CamScan is a light weight app that lets you manage your documents easily. You can create new documents or modify the existing
ones.
The app is totally free and there are no ads as well.
The app does NOT require internet connection for any of the feature.
The app gives you features like:
a) Create PDF
b) Encrypt PDF
c) Decrypt PDF
d) Add Watermarks
e) Rotate Pages
f) Merge PDF
g) Split PDF
h) Compress PDF
i) Add Pages to PDF
j) Remove Pages from PDF
k) Reorder Pages
l) PDF to Image Conversion
and many more features are on the way...