Zenkit

You can upload as many files, documents, images or attachments as you'd like to any task in Zenkit To Do. 

On the desktop and web app, you can simply drag and drop files onto the task to add them. Alternatively, click into the Attachments field to open the file explorer on your device or connect with Google Drive, Box, or Dropbox. If you choose "Drawing", a canvas will open that allows you to draw anything you like. 

On the mobile app, tap the Attachments field to take a photo or choose a file from your device. You can also share to Zenkit To Do from the sharing tray.