Quite a few things out there that can manage that, I’m currently using FSNotes on iOS, but for years I used simplenote / notational velocity - as easy as it gets for data entry
Thinktype works a lot like notational velocity (write and search at the same time), but it's actually even easier because it doesn't have titles. You can write the entire note from the searchfield. (I'm comparing it to a web app inspired by notational velocity here[1], never used the original because I don't have a mac.)