PDF tools app is very useful. This app contains the most useful features of PDF. This app has useful features like compress PDF, convert to PDF or unlock PDF
You can choose the file easily from your iCloud account, and perform whatever operation you want. You can compress it by just tapping the compress button, or if you want to convert PPT or Word(DOC) file into PDF then that is also very easy.
Even you can remove or change the password of PDF. For that, you just have to choose PDF file and unlock it
You can see recent files list from header button.