Blending in is only a question of having the app icon next to similar ones in colour and design. Also it could make it harder to find. I think the best practice

Blending in is only a question of having the app icon next to similar ones in colour and design. Also it could make it harder to find. I think the best practice is to make your icon stand out and not blend in. Which might be a bit interesting for an app about anonymity. :)