My rating would've been higher if I was actually able to use Neon . Neon itself seems amazing and as an artist I would use it daily if the option was available. I was only able to try the features a couple times before the pop up came up saying that if I would like to continue I needed to purchase this app Pro to be able to capture unlimited colors and gradients. To put out a free app and then make the users pay for the main feature is ridiculous. If you want someone to buy your app, make it $1.99 to download it instead.
Making the Image Pallet Stickers, Alternate App Icons, and Random Gradients behind a pay wall makes sense, they're additions that won't take away from the main function, the apps purpose, and the apps general functionality.
The ICloud Sync feature I feel shouldn't be behind a pay wall either, it's a complete pain, but at least it doesn't make it unusable and pointless to download.
If you were to put additional captures behind ad walls so for instance watching an ad and then getting 5 more captures, I would definitely continue using your app. It would be a bit of a pain to some, but I don't mind watching ads for apps that I love to use and serve their purpose(especially ones that do it well).
If you ever decide to update your app and make it more functional, I would love to use it again. I think it has a lot of potential and would be very helpful to many artists like myself.