Answer:
Before you uninstall or re-install CollaNote or Updating a big update in CollaNote, make sure that you BACKUP all of your precious notes to iCloud before proceeding with anything else. The steps below show how to backup your precious CollaNotes’ notes and/or PDF in a simple way.

• Step 1: In the begin screen, long press the notes/pdf/folder that you want to backup. The organize mode will turn on

Answer: This is the lasso tool - The group editing tool
(Lasso tool picture)

Lasso tool has 2 way to select a group:

• Rectangular selection
• Freeform selection

Answer: This is the curve tool

Answer:

• Step 1: Create a new Note | In the Start Screen > Right “+” button > Create new Note > Note name: [SomeName] > Create Note
  (picture of new note)
• Step 2: Invite the person | In the Note screen > Right side “Friends” button > Input “nickname” > Invite
  (picture of invite)

Answer: In the Note screen > Left “Menu” setting > Most Used > Print,share & backup > Export this Note

Answer: Step 1: In the Start Screen > Right “Menu” setting > Import PDF

Short Answer: If you didn’t backup the files before deleting/reinstalling Collanote, then NO, there is no known method to get those notes back.